Doctor of Philosophy, University of Tokyo

Master of Engineering, The University of Tokyo

Mechanical properties

Mechanical engineering in general

Nanomaterials

Strength of materials in general

Nanotechnology/Materials, Nanostructure physics

Nanotechnology/Materials, Nanomaterials

Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Machine materials and mechanics

Jun. 2002
Faculty of Electro-Communications, University of Electro-Communications, Professor

Jan. 1992 - May 2002
電気通信大学電気通信学部, 助教授

Mar. 1982
University of Tokyo, School of Engineering, Department of Aeronautics

Mar. 1979
University of Tokyo, School of Engineering, Department of Aeronautics

Mar. 1977
University of Tokyo, Faculty of Engineering, Department of Aronautics

1993 - 2013
第２企画委員会委員, 日本材料科学会, Society

2005
第１企画委員会委員, 日本材料科学会, Society

2005
理事, 日本材料科学会, Society

1995 - 2004
評議員, 日本材料科学会, Society

1999 - 2001
将来検討委員会委員, 日本材料科学会, Society

1987 - 1991
編集委員会委員, 日本材料科学会, Society

Jun. 2013
日本材料科学会
日本材料科学会功労賞

Reduction of the thermal conductivity of a graphene/hBN heterobilayer: Via interlayer sp3 bonds
T. Iwata; K. Shintani
Physical Chemistry Chemical Physics, Royal Society of Chemistry, 20, 7, 5217-5226, 2018, Peer-reviwed, Thermal conductivities (TCs) of graphene (g)/hexagonal boron nitride (hBN) heterobilayers with interlayer sp3 bonds are computed using nonequilibrium molecular dynamics (NEMD) simulations. It is revealed that the TC of a g/hBN heterobilayer drastically decreases if there is even a few interlayer sp3 bonds, and continues to gradually decrease upon increasing their fraction up to 0.25, where the fraction of the interlayer sp3 bonds is defined by the atomic fraction of interlayer-sp3-bonded carbon atoms within graphene constituting a g/hBN heterobilayer. If their fraction exceeds 0.25, the TC of a g/hBN heterobilayer gradually increases, namely, the TC of a g/hBN heterobilayer takes a minimum at the fraction of 0.25 of the interlayer sp3 bonds. In order to understand such a behavior of the TC of the heterobilayer, the local phonon density of states (DOSs) in each of the two layers is calculated. By examining the local phonon DOSs, it was found that the existence of the minimum TC of the heterobilayer can be understood by considering both the phonon scattering and the characteristic change of the heterobilayer structure. In the range of the low fractions of interlayer sp3 bonds, the van der Waals (vdW) interactions are predominantly effective for binding the two layers, and the interlayer sp3 bonds act as phonon scatterers like defects to make the TC of the heterobilayer decrease. Upon increasing the fraction of interlayer sp3 bonds, the contribution of the interlayer sp3 bonds to the unification of the two layers becomes stronger, and hence the rigidity of the heterobilayer structure gradually increases. If their fraction exceeds 0.25, the heterobilayer structure approaches a quasi-three-dimensional one, so that the TC of the heterobilayer increases. These findings will be useful for tuning the TCs of g/hBN heterobilayers via interlayer sp3 bonds.
Scientific journal, English

Dynamic encapsulation of corannulene molecules into a single-walled carbon nanotube
Y. Joko; R. Sasaki; K. Shintani
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, ROYAL SOC CHEMISTRY, 19, 40, 27704-27715, Oct. 2017, Peer-reviwed, The morphology of corannulene molecules encapsulated in a single-walled carbon nanotube (SWCNT) is addressed using atomistic simulations. Firstly, dynamic simulation (DS) of encapsulation of corannulene molecules into a SWCNT is performed using a molecular dynamics (MD) method. It is revealed that corannulene molecules encapsulated in a SWCNT tend to form concave-concave (CC) dimers, and these dimers make stacks tilting against the SWCNT axis or take an arrangement such that their convex surfaces face the inner wall of the SWCNT. This tendency arises from the fact that the van der Waals interactions between the convex surfaces of the corannulene molecules and the inner wall of the SWCNT dominate in their dynamic encapsulation into the SWCNT, and CC dimers are favored based on the energetics. Next,conjugate gradient (CG) energy minimizations starting from two kinds of initial arrangement of corannulene molecules in a SWCNT, concave-convex (CV) and CC/convex-convex (W) arrangements, are performed.The CG energy minimizations confirm the result of DS that CC dimers are the structural motif of corannulene molecules in a SWCNT. From the final configurations of both the simulations, the tilt angles and Intermolecular distances of the stacked molecules are calculated. With increasing the SWCNT diameter, the tilt angles decrease while the inter molecular distances remain almost constant. The tilt angles of the stacked corannulene molecules are approximately expressed by a semi-analytical form ula which is derived on the basis of a geometrical constraint condition.
Scientific journal, English

Thermal rectification characteristics of graphene nanoribbons of asymmetric geometries
T. Iwata; K. Shintani
MRS Advances, Materials Research Society, 2, 1, 15-20, 2017, Peer-reviwed, The rectification of heat in graphene nanoribbons (GNRs) of asymmetric geometries is investigated by means of nonequilibrium molecular dynamics (NEMD). Two kinds of geometries of GNRs are addressed
a trapezoidal or T-shaped step is inserted halfway through a GNR in its longitudinal direction. The thermal conductivities (TCs) of the GNRs in the two longitudinal directions, forward and backward, are calculated making their width and temperature change. It is revealed that the thermal rectification ratio (TRR) of T-shaped GNRs are larger than those of trapezoidal GNRs and that the characteristics of heat transport in such asymmetric GNRs can be understood by considering the local phonon density of states (DOSs).
International conference proceedings, English

Hardness of Pillared-Graphene nanostructures via indentation simulation
R. Sasaki; K. Shintani
MRS Advances, Materials Research Society, 2, 1, 45-50, 2017, Peer-reviwed, Pillared-graphene is one of nanocarbon hybrids. It consists of graphene sheets and carbon nanotubes (CNTs)
the latter are bonded vertically to the former. In order to investigate the hardness of pillared-graphene, indentation simulations are performed using a molecular dynamics method. It is revealed that the hardness of pillared-graphene increases with increasing the diameter of the CNTs, whereas it decreases with increasing the distance between CNTs or temperature. Such tendencies can be understood by considering the deformations of graphene and CNTs individually.
International conference proceedings, English

Mechanical Properties of Nanocarbon Hybrid Films via Indentation Simulation
T. Onodera; K. Shintani
MRS Advances, Materials Research Society, 1, 19, 1383-1388, 2016, Peer-reviwed, The mechanical properties of nanocarbon hybrid films are addressed by means of indentation simulation based on molecular-dynamics. In these films, single-walled carbon nanotubes (SWCNTs) are intercalated parallel to each other between graphene sheets
the SWCNT axes are also parallel to the planes of the sheets. Thus the simulation model is quasi-two-dimensional. The load-deflection curve depends on both the number of the layers and the diameter of SWCNTs. In the range of small forces, the simulation data can be interpolated by a cubic function of the deflection, while in the range of large forces, the data can be expressed in terms of a linear function of the deflection. It is revealed that such a transition corresponds to the structural change of the hybrid film.
International conference proceedings, English

Geometrical constraint on stacking of polycyclic aromatic hydrocarbon molecules encapsulated in a single-walled carbon nanotube
K. Mouri; K. Shintani
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, ROYAL SOC CHEMISTRY, 18, 45, 31043-31053, 2016, Peer-reviwed, The stacking morphologies of polycyclic aromatic hydrocarbon (PAH) molecules encapsulated in a single-walled carbon nanotube (SWCNT) are investigated by using a molecular-dynamics (MD) method. The encapsulating SWCNTs are of twenty different diameters. For coronene molecules, both conjugate-gradient (CG) energy minimization of the stacked molecules in a SWCNT and dynamics simulation (DS) of encapsulation of the molecules in a SWCNT are performed; while for sumanene molecules, only DS of encapsulation of the molecules in a SWCNT is performed. The tilt angles and intermolecular distances are calculated from the final configurations via CG and DS. On the assumption that the morphologies of the molecules in a SWCNT are determined by the geometrical constraint condition, semi-analytical formulas for the dependence of the tilt angles of the molecules on the SWCNT diameter are derived. These formulas are expressed in terms of the inverse functions of cosine the arguments of which are linear functions of the SWCNT diameter, and successfully agree with the simulation data. Accordingly, they are useful for controlling the tilt angles of the PAH molecules encapsulated in a SWCNT by adjusting the SWCNT diameter. It is also revealed that the stacking geometry of sumanene molecules with small tilt angles in a SWCNT is consistent with that of a sumanene dimer in a free space which Karunarathna and Saebo (Struct. Chem., 2014, 25, 1831) obtained using ab-initio calculations.
Scientific journal, English

Morphology of a columnar stack of coronene molecules encapsulated in a single-walled carbon nanotube
Y. Sakane; K. Mouri; K. Shintani
AIP ADVANCES, AMER INST PHYSICS, 5, 11, 117113-(18 pages), Nov. 2015, Peer-reviwed, The morphology of stacked coronene molecules encapsulated in a single-walled carbon nanotube (SWCNT) is investigated using atomistic simulation. First, the minimum energy configuration of coronene molecules in a SWCNT is sought by means of conjugate gradient (CG) minimization. Secondly, encapsulation of coronene molecules into a SWCNT existing in a coronene atmosphere is simulated by means of molecular dynamics (MD). In both of the simulations, the diameter of the SWCNT ranges from 1.35 to 1.69 nm, and the final configurations of coronene molecules within a SWCNT are examined. In a thin SWCNT, coronene molecules tilt against the radial direction of the SWCNT and slide relative to each other, whereas in a thick SWCNT, they do not tilt but rotate relative to each other. In a SWCNT of the intermediate diameter, they tilt, slide, and rotate. For the SWCNT diameter less than or equal to 1.52 nm, the mean tilt angle of the stacked coronene molecules almost linearly decreases with increasing the diameter, whereas for the diameter above 1.52 nm, it is approximately 0 degrees. To check the validity of the results, the MD simulations are performed changing the density of the coronene atmosphere and the length of the SWCNT; the results prove to be valid. Finally, the effects of temperature on the mean tilt angle and mean intermolecular distance of stacked coronene molecules are examined by a rather simplified simulation, which shows that both of them increase with increasing temperature. (C) 2015 Author(s).
Scientific journal, English

Thermal properties of pillared-graphene nanostructures
M. Rifu; K. Shintani
Materials Research Society Symposium Proceedings, Cambridge University Press, 1727, mrsf14-1727-K15-30-1-6-(6 pages), Feb. 2015, Peer-reviwed, The thermal conductivities of pillared-graphene nanostructures (PGNSs) are obtained using nonequilibrium molecular-dynamics simulation. It is revealed their thermal conductivities are much smaller than the thermal conductivities of carbon nanotubes (CNTs). This fact is explained by examining the density of states (DOS) of the local phonons of PGNSs. It is also found the thermal conductivity of a PGNS linearly decreases with the increase of the inter-pillar distance.
International conference proceedings, English

Electronic properties of monolayer molybdenum dichalcogenides under strains
J. Sugimoto; K. Shintani
Materials Research Society Symposium Proceedings, Materials Research Society, 1726, mrsf14-1726-J12.21-1-6-(6 pages), 2015, Peer-reviwed, The electronic band structures of monolayer molybdenum dichalcogenides, MoS2, MoSe2, and MoTe2 under either uniaxial or biaxial strain are calculated using first-principles calculation with the GW method. The imposed uniaxial strain is in the zigzag direction in the honeycomb lattice whereas the imposed biaxial strain is in the zigzag and armchair directions. It is found that the band gaps of these dichalcogenides almost linearly increase with the decrease of the magnitude of compressive strain, reach their maxima at some compressive strain, and then decrease almost linearly with the increase of tensile strain. It is also found their maximum band gaps are direct bandgaps.
International conference proceedings, English

Structures and electronic properties of graphene with vacancy defects
J. Sugimoto; K. Shintani
Materials Research Society Symposium Proceedings, Materials Research Society, 1658, January, 70-75, 2014, Peer-reviwed, The structures and electronic properties of graphene with defects consisting of one to six atomic vacancies are investigated using first-principles calculation. All of the geometrically possible initial structures of a movacancy or a multivacancy in graphene are equilibrated. The formation energies and electronic band structures for the equilibrated defective structures are calculated. It is suggested non-zero bandgaps may be induced in graphene by introducing some types of monovacancy or multivacancy although further checks regarding supercell size are necessary to ensure the present results.
International conference proceedings, English

Electronic properties of hydrogenated graphene-like materials under strains
K. Mihara; K. Shintani
Materials Research Society Symposium Proceedings, Materials Research Society, 1658, January, 76-81, 2014, Peer-reviwed, The electronic band structures of the hydrogenated graphene-like materials, graphane, silicane, and germanane, under tensile strains are calculated using first-principles calculation. The imposed tensile strain is in either the armchair or zigzag direction in the honeycomb lattice. It is found that the band gap of graphane gradually increases with the increase of the strain, whereas the band gaps of silicane and germanane decrease with the increase of the strain. There is little effect of the direction of the imposed strain on such strain dependences.
International conference proceedings, English

Morphology of a graphene nanoribbon encapsulated in a carbon nanotube
F. Furuhashi; K. Shintani
AIP ADVANCES, AMER INST PHYSICS, 3, 9, 092103-(13 pages), Sep. 2013, Peer-reviwed, The morphologies of graphene nanoribbons (GNRs) encapsulated in single-walled carbon nanotubes (SWNTs) are investigated using molecular-dynamics (MD) simulation. The GNRs are assumed to be hydrogen-terminated and formed by connecting polycyclic aromatic hydrocarbons, perylene or coronene molecules. The combined structures consisting of a GNR and an encapsulating SWNT are equilibrated at room temperature. It is shown that if the diameter of a SWNT is larger than the sum of the width of the GNR and twice the length of a C-H bond, a twisted GNR is obtained, whereas if the diameter of a SWNT is smaller than the sum of the two, the cross section of the SWNT cannot maintain its original circular shape and elliptically distorts, and a non-twisted GNR or a twisted GNR of long pitch is obtained. The estimated pitch of a regularly-twisted GNR agrees with the experimentally observed one in order of magnitude. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.
Scientific journal, English

First-Principles Calculation of the Electronic Properties of Single-Walled Carbon Nanotubes under Torsions
K. Mihara; K. Shintani
Materials Research Society Symposium Proceedings, 1505, mrsf12-1505-w03-58 (6 pages), Mar. 2013, Peer-reviwed
International conference proceedings, English

Mechanical Properties of Pillared-Graphene Nanostructures under Shear Loads
H. Sasaki; T. Hagi; K. Shintani
Materials Research Society Symposium Proceedings, 1505, mrsf12-1505-w10-27 (6 pages), Mar. 2013, Peer-reviwed
International conference proceedings, English

Atomistic study of the morphology of graphene on Si and SiC substrates
S. Seto; N. Arai; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1407 (Carbon Nanotubes, Graphene and Related Nanostructures), 1407, mrsf11-1407-aa15-47 (6 pages), Feb. 2012, Peer-reviwed
International conference proceedings, English

Controlling out-of-plane deformations of graphene nanobridges
T. Nakajima; K. Shintani
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, WILEY-BLACKWELL, 248, 12, 2839-2847, Dec. 2011, Peer-reviwed, Graphene nanoribbons (GNRs) can be applied to transistors, mass sensors, and dust detectors. Suspended GNRs which connect terminals in electronic devices like bridges can be treated as edge-constrained GNRs. In this paper, edge-constrained GNRs of various sizes and initial strains are studied using molecular dynamics (MD) simulations. To induce strain in GNRs, bond lengths between carbon atoms of the initial configurations of GNR models are varied. The bond length of the energetically stable GNRs is estimated at 1.47 angstrom. At this bond length, GNRs obviously change the tendencies of their energies, amplitudes, and deformations. The relationships between the out-of-plane deformations and the sizes of GNRs, and between the out-of-plane deformations and strains of GNRs are studied. Under compressive strain, the out-of-plane deformation of GNRs is dominantly caused by buckling. The amplitude of the buckling decreases as GNRs elongate. On the other hand, under tensile strain, the out-of-plane deformation of GNRs is caused by ripples and thermal vibrations. The ripples show regular patterns. It is suggested we can control the amplitudes of the out-of-plane deformations and ripple patterns of GNRs by adjusting their strain. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Scientific journal, English

Atomistic study of the mechanical stability of multi-layered graphene nanobridges
T. Nakajima; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1297 (Deformation Mechanisms, Microstructure Evolution and Mechanical Properties of Nanoscale Materials), 1297, mrsf10-1297-p10-21(6pages), Mar. 2011, Peer-reviwed
International conference proceedings, English

Atomistic study of the mechanical properties of metallic-glass nanowires
K. Koshiyama; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1297 (Deformation Mechanisms, Microstructure Evolution and Mechanical Properties of Nanoscale Materials), 1297, mrsf10-1297-p10-20(6pages), Feb. 2011, Peer-reviwed
International conference proceedings, English

Structural and electronic properties of strained graphene nanoribbons modified by molecules
T. Urakawa; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1204 (Nanotubes and Related Nanostructures, edited by Y. K. Yap, Warrendale, PA), 1204-K14-35(6pages), Feb. 2010, Peer-reviwed
International conference proceedings, English

Molecular dynamics study of energetics of graphene flakes
T. Nakajima; K. Shintani
Journal of Applied Physics, 106, 114305 (This paper was one of, Dec. 2009, Peer-reviwed
Scientific journal, English

Molecular dynamics of carbon nanobearings
K. Sato; N. Arai; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1204 (Nanotubes and Related Nanostructures, edited by Y. K. Yap, Warrendale, PA), 1204-K05-79(6pages), Dec. 2009, Peer-reviwed
International conference proceedings, English

Nanomechanical study of synthesis of metallic core-shell clusters via coalescence
S. Mizuno; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1130E (Computational Materials Design via Multiscale Modeling, edited by Y. Qi, H. E. Fang, N. Reynolds, and Z.-K. Liu, Warrendale, PA), 1130-W12-19(6pages), Feb. 2009, Peer-reviwed
International conference proceedings, English

Atomistic study of creation of bimetallic clusters by coalescence
S. Mizuno; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1087E (Crystal-Shape Control and Shape-Dependent Properties ― Methods, Mechanism, Theory, and Simulation, edited by A.S. Barnard, K. Choi, D.J. Srolovitz, and H. Xu, Warrendale, PA), 1087-V08-01(6pages), Apr. 2008, Peer-reviwed
International conference proceedings, English

Damping Characteristics of Commensurate Double-Walled Carbon Nanotube Oscillators
Y. Ooi; K. Shintani
Materials Research Society Symposium Proceedings Vol. 1057E (Nanotubes and Related Nanostructures, edited by Y. K. Yap, Warrendale, PA), 1057-II10-17(6 pages), Feb. 2008, Peer-reviwed
International conference proceedings, English

Interface morphology of metallic multilayers by means of deposition simulation
K. Shintani; Y. Kometani; T. Nakajima; Y. Yano
Materials Research Society Symposium Proceedings Vol. 962E (Nanoscale Magnets ― Synthesis, Self-Assembly, Properties and Applications, edited by J. Fassbender, J. Chapman, and C.A. Ross), 0962-P09-03 (6 pages), Feb. 2007, Peer-reviwed
International conference proceedings, English

Mechanical properties of Si/Ge core-shell nanowires under a uniaxial tension
Y. Yano; T. Nakajima; K. Shintani
Materials Research Society Symposium Proceedings Vol. 958 (Group IV Semiconductor Nanostructures, edited by C. Delerue, L. Tsybeskov, D. J. Lockwood, M. Ichikawa, and A. W. van Buuren), 0958-L10-17 (6 pages), Feb. 2007, Peer-reviwed
International conference proceedings, English

Molecular-dynamics study of the morphological evolution of a metallic cluster deposited on a surface
K. Shintani; K. Terajima; Y. Kometani
Materials Research Society Symposium Proceedings Vol. 924E (Mechanics of Nanoscale Materials and Devices, edited by A. Misra, J.P. Sullivan, H. Huang, K. Lu, and S. Asif), 0924-Z08-05 (6 pages), Jun. 2006, Peer-reviwed
International conference proceedings, English

Molecular-dynamics study of SiGe epitaxy on a Si substrate
K. Shintani; Y. Yano; M. Abe
physica status solidi (c) (Proceedings of the 32nd International Symposium on Compound Semicondutors, Rust, Germany, 18-22 Sep. 2005), WILEY-VCH, 3, 3, 701-704, Mar. 2006, Peer-reviwed
International conference proceedings, English

Atomistic study of the mechanical properties of one-dimensional nanomaterials
K. Shintani; S. Kameoka; S. Sato; Y. Kometani
Materials Research Society Symposium Proceedings Vol. 901E(Assembly at the Nanoscale -- Toward Functional Nanostructured Materials, edited by C. S. Ozkan, F. Rosei, G. P. Lopinski, and Z. L. Wang), 0901-Ra22-19-Rb22-19 (6 pages), Feb. 2006, Peer-reviwed
International conference proceedings, English

Molecular-dynamics study of the structural dependence of the Young modulus of Au nanowires
S. Kameoka; K. Shintani
Materials Research Society Symposium Proceedings Vol. 818 (Nanoparticles and Nanowire Building Blocks-Synthesis, Processing, Characterization and Theory, edited by O. J. Glembocki and C. E. Hunt), M8.14.1-M8.14.6 (6 pages), Jul. 2004, Peer-reviwed
International conference proceedings, English

Molecular-dynamics analysis of morphological evolution of softly deposited Au nanoclusters
K Shintani; Y Taniguchi; S Kameoka
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 95, 12, 8207-8215, Jun. 2004, Peer-reviwed, The initial period following deposition of soft-landing Au clusters is investigated by classical molecular-dynamics simulation. The embedded-atom method potential is adopted for the interaction between Au atoms. Clusters of specified sizes are cut out of the bulk crystal structure. Whether a cluster equilibrated at a given temperature is in a solid state or in a liquid state is judged by tracking the trajectory of an atom in the cluster and by examining the radial distribution function. The deposition simulation reveals that there is an energy barrier in the morphological accommodation of a cluster to the substrate if the cluster is crystalline before deposition, and is equilibrated at a temperature different from that of the substrate. On the other hand, there is no energy barrier in the morphological accommodation of a cluster that is in a liquid state before deposition. Exceptionally, a crystalline cluster that is nearly at a melting temperature can accommodate itself smoothly to the substrate maintained at the same temperature without an energy barrier. (C) 2004 American Institute of Physics.
Scientific journal, English

Atomistic model of limited-thickness Si(001) epitaxy at low temperatures
K Shintani; T Nakajima; S Kameoka
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 95, 2, 446-453, Jan. 2004, Peer-reviwed, Limited-thickness homoepitaxial growth on a Si(001) surface at low temperatures is investigated by using the classical molecular-dynamics method with the Stillinger-Weber potential. The simulation begins with preliminary equilibration of the substrate at a specified temperature. 256 silicon atoms with the energy of 0.2 eV are then deposited one by one on the substrate. The simulations are performed at the temperatures 300, 500, 700, and 1000 K. At 300 and 500 K, the initial three or four monolayers grow epitaxially, and the subsequent layers form amorphouslike structures. At 700 and 1000 K, the deposited atoms form epitaxial structures throughout the simulation. In the epitaxial growth mode, 2x1 dimer rows are observed to align along alternately perpendicular <110> directions in successive atomic layers. Tracking a few atoms on the substrate surface reveals that these transient anisotropic surface structures are created by the breaking and reconstruction of dimers due to the impingement of deposited atoms even if the diffusion length of the adatoms is small. We conclude that breakdown of epitaxy occurs when such renewal of surface dimers ceases to be repeated. (C) 2004 American Institute of Physics.
Scientific journal, English

Atomistic study of strain dependence of Poisson's ratio of single-walled carbon nanotubes
K Shintani; T Narita
SURFACE SCIENCE, ELSEVIER SCIENCE BV, 532, 862-868, Jun. 2003, Peer-reviwed, The Poisson ratio of single-walled carbon nanotubes is calculated by the molecular-dynamics simulations. The result shows that the Poisson ratio depends on both the imposed strain and the chirality. Such dependences are addressed from the viewpoint of mechanics of the honeycomb lattice of nanotubes. It is shown that the changes of bond angles of the honeycomb lattice of nanotubes due to deformation tend to decrease the Poisson ratio. On the other hand, the increase of the chiral angle would tend to increase the Poisson ratio if it was not for deformation of the honeycomb lattice. In the simulation results, the Poisson ratio decreases with the increase of strain and chiral angle, which implies that the changes of bond angles in the honeycomb lattice dominantly determine the Poisson ratio of single-walled carbon nanotubes. (C) 2003 Published by Elsevier Science B.V.
Scientific journal, English

Molecular-dynamics study of the mechanical properties of metallic nanowires
T Nakajima; K Shintani
THREE-DIMENSIONAL NANOENGINEERED ASSEMBLIES, MATERIALS RESEARCH SOC, 739, 145-150, 2003, Peer-reviwed, The method of molecular-dynamics is employed to simulate and investigate the deformation of metallic nanowires under tensile strain. The interactions between metallic atoms are calculated by using the embedded-atom method potential. A model nanowire is preliminarily equilibrated at a specified temperature. Then, the uniform uniaxial extension of the nanowire is performed. The thinning process of a metallic nanowire is observed in the sequential snapshots of its morphological change.
International conference proceedings, English

Molecular-dynamics simulation of the initial period of cluster deposition
K Shintani; T Nakajima; Y Taniguchi
MORPHOLOGICAL AND COMPOSITIONAL EVOLUTION OF THIN FILMS, MATERIALS RESEARCH SOCIETY, 749, 361-366, 2003, Peer-reviwed, The initial periods of deposition process of metal clusters in the soft-landing regime are investigated by the molecular-dynamics simulation. The embedded-atom method potential is adopted for calculation of the interaction between metallic atoms. The predictor-corrector method for second-order differential equations is employed for integration of the equations of motion. A simulation begins with equilibration of clusters and a substrate at a specified temperature. The lowest atomic layer in the substrate is fixed and the next few atomic layers are set to be velocity-scaling layers during the deposition process. The periodic boundary conditions are imposed in the horizontal directions. A single cluster with no velocity is deposited on the substrate. The simulations are performed at different temperatures of the clusters and substrate and for different sizes of clusters. How the morphological transition of the deposited nanostructures is affected by these parameters is discussed.
International conference proceedings, English

Molecular-dynarnics modelling of the tensile deformation of helical nanowires
K Shintani; S Kameoka
MECHANICAL PROPERTIES DERIVED FROM NANOSTRUCTURING MATERIALS, MATERIALS RESEARCH SOC, 778, 195-200, 2003, Peer-reviwed, Deformations of Au nanowires of helical structures under enforced elongation are addressed by the molecular-dynamics simulation. The embedded-atom method potential is employed for calculating the interaction between Au atoms. Model nanowires of the two kinds of helicities are prepared. Before elongation, a model nanowire is equilibrated at a specified temperature. Then, the Au atoms at one end of the nanowire are translationally moved in the axial direction. The simulation results show that a model nanowire can be elongated to form a single-atom chain of Au atoms under some circumstances.
International conference proceedings, English

Molecular-dynamics study of morphology of deposited silicon atoms
K. Shintani; T Nakajima
International Conference on Multiscale Materials Modelling, Abstracts, 141, Jun. 2002, Peer-reviwed, The morphology of deposited silicon atoms during the initial period of molecular beam epitaxial growth is investigated using molecular dynamics simulation. It is revealed at 500K, the initial two or three atomic layers grow irregularly, and subsequent layers grow epitaxially, the initial layers being transformed into the epitaxial layers, whereas at and above 600K, the deposited atoms grow epitaxially. It is also found that in the epitaxial growth mode, 2×1 dimer rows are on the way to be formed at each atomic layer, and these dimer rows tend to be aligned along the alternate perpendicular <110> directions in the successive atomic layers.
International conference proceedings, English

Atomistic study of strain dependence of Poisson's ratio of single-walled carbon nanotubes
K. Shintani; T. Narita
7th International Conference on Nanometer-Scale Science and Technology/21st European Conference on Surface Science, Proceedings CD, 発表番号MO-P-005, Jun. 2002, Peer-reviwed, The dependence of the Poisson's ration on the imposed strain and the chirality is discussed based on the mechanical view point of the honeycomb lattice of carbon nanotubes. It is revealed that the change of the bond angles of the honeycomb lattice due to deformation tends to decrease the Poisson's ratio, whereas the increase of the chiral angle would tend to increase the Poisson's ratio if it were not for deformation of the honeycomb lattice. In the simulation results, the Poisson's ratio decreases with the increase of strain and chiral angle, which implies that the change of the bond angles in the honeycomb lattice dominantly determine the Pisson's ratio of carbon nanotubes.
International conference proceedings, English

Atomistic simulations of deposition processes of epitaxial layers
K Shintani; H Sugii; M Nishimura; T Nakajima
CURRENT ISSUES IN HETEROEPITAXIAL GROWTH-STRESS RELAXATION AND SELF ASSEMBLY, MATERIALS RESEARCH SOCIETY, 696, 39-44, 2002, Peer-reviwed, The deposition process of epitaxial layers is simulated by the method of molecular dynamics. The interaction forces between atoms are calculated using the Stillinger-Weber potential. Before the deposition of atoms, the substrate is equilibrated at a specified temperature. Atoms with identical initial velocities and with initial coordinates selected at random in the plane parallel to the growth surface arrive at the substrate to form an overlayer. During the deposition, the lower part of the substrate is held at an initially specified temperature by velocity scaling. How the growth morphology of an overlayer is influenced by the substrate temperature is investigated in connection with the behavior of deposited atoms.
International conference proceedings, English

Atomistic study of mechanical properties of carbon nanotubes
T Narita; K Shintani
MAKING FUNCTIONAL MATERIALS WITH NANOTUBES, MATERIALS RESEARCH SOCIETY, 706, 283-288, 2002, Peer-reviwed, The mechanical properties of single-walled carbon nanotubes are investigated by means of molecular dynamics simulations. The Tersoff-Brenner potential is used for the calculation of the interatomic forces. Two kinds of simulation cells are considered; one adopts the periodic boundary condition along the tube axis and the other corresponds to tube clusters. The atoms at the ends of a simulation cell are translated along its axis, and the Young's modulus and Poisson's ratio are estimated. How these mechanical properties of carbon nanotubes depend on their chiralities is discussed.
International conference proceedings, English

Atomistic study of strain profiles in semiconductor quantum dot structures
K. Shintani; H. Sugii; Y. Kikuchi; M. Kobayashi
Materials Research Society Symposium Proceedings Vol. 642 (Semiconductor Quantum Dots II, edited by R. Leon, S. Fafard, D. Huffaker, and R. Notzel), J3.2.1-J3.2.6, Feb. 2001, Peer-reviwed, The minimum energy atomic configurations of stacked GaAs/InAs/GaAs quantum dot structures are calculated by using conjugate gradient energy minimization with the Stillinger-Weber potential. The islands are assumed to be either of pyramidal shape or of trapezoidal shape. The numerical results for the five-layer stacked structures show that the normal strains exhibit stepwise up-and-down profiles through the vertical centerlines of the islands and intermediate layers. Next, the molecular dynamics method with the Tersoff potential is applied to single Ge/Si and Si/Ge/Si structures with pyramidal islands in order to investigate the effect of temperature. It is found there is a considerable difference between the normal strain in the direction perpendicular to the island base obtained by the conjugate gradient minimization with the Stillinger-Weber potential and that obtained by the molecular dynamics method at 800 K.
International conference proceedings, English

Strain profiles in pyramidal quantum dots by means of atomistic simulation
Y Kikuchi; H Sugii; K Shintani
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 89, 2, 1191-1196, Jan. 2001, Peer-reviwed, The minimum energy configurations of the atomic structure of a Ge island on a Si(001) substrate are calculated by using the conjugate gradient minimization of the potential energy of the system. The island is assumed to be covered or uncovered by a Si layer and assumed to be of pyramidal shape with the sidewalls of {110} or {105} facets; the base length of the island ranges from 5.43 to 10.9 nm. Two empirical potentials, the Keating and Stillinger-Weber potentials, are used. At the interfaces between the regions occupied by the atoms of different species, the potential parameters for such bondings are properly adopted. The strain profiles along the three selected paths within the structure and along the cap surface are calculated. While the profiles of the normal strain component epsilon (xx) obtained by the two potentials are in good agreement with each other except within the substrate and at the edges of the island in the uncovered structures, the two profiles of the normal strain component epsilon (zz) show a considerable difference in their magnitude, and the use of the Stillinger-Weber potential is recommended for the islands of the small sizes below 10 nm. The validity of the valence force field model with the Keating potential for such small islands is questionable although this model is widely recognized to be applicable to the calculation of strains in the quantum dot structures. The strain relaxation in the uncovered island is discussed through the comparison with that in the covered island. The strain profile along the cap surface explains vertical self-organization of stacked dots. (C) 2001 American Institute of Physics.
Scientific journal, English

Elastic energy approach to the strain relaxation mechanism by dislocation splitting and slip in twist-bonded substrates
Y Obayashi; K Shintani
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 88, 10, 5623-5629, Nov. 2000, Peer-reviwed, The strain relaxation mechanism by the splitting and slip of a cross grid of dislocations in a heteroepitaxial film on a thin twist-bonded substrate is analytically investigated by considering the energy change due to the slip of the dislocation arrays. In this mechanism, the dislocation arrays resulting from the splitting of a cross grid of screw dislocations in the interface between the twist-bonded substrate and the supporting bulk substrate move toward the interface between the heteroepitaxial film and the twist-bonded substrate so that the mismatch strain is relieved. The energy change consisting of the interaction energy between the dislocation arrays and their images and the interaction energy between the two split dislocation arrays is obtained in the semi-infinite isotropic elastic solid. If the initial screw dislocation arrays dissociate into two partial dislocation arrays, the stacking fault energy must be added in the energy change. The thickness of the twist-bonded substrate at the zero of the energy change becomes the critical thickness at which the strain relaxation mechanism can be operative. The results show that the strain relaxation due to the slip of 60 degrees perfect dislocation arrays does not tend to occur while the strain relaxation due to the slip of 30 degrees partial dislocation arrays is possible if the twist angle is low and if the thickness of the twist-bonded substrate is small. Whether this mechanism was possible in the experiments in the literature is discussed. (C) 2000 American Institute of Physics. [S0021-8979(00)01023-9].
Scientific journal, English

Critical thickness of a heteroepitaxial film on a twist-bonded compliant substrate
Y Obayashi; K Shintani
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 88, 1, 105-114, Jul. 2000, Peer-reviwed, The critical thickness for misfit dislocation formation in a heteroepitaxial film on a twist-bonded compliant substrate is calculated. The boundary between the twist-bonded compliant substrate and the supporting bulk substrate with a low twist angle is assumed to be represented by a cross grid of straight dislocations. The critical thickness is determined by the zero of that formation energy of a misfit dislocation which consists of the self-energy of the dislocation, the interaction energy between the dislocation and the dislocation arrays in the twist boundary, and the interaction energy between the dislocation and the mismatch strain. Numerical results for the InxGa1-xP film on a twist-bonded GaAs compliant substrate show that the critical thickness of the film on a twist-bonded compliant substrate is considerably larger than that of the film on a free-standing compliant substrate. This difference in critical thicknesses for the twist-bonded compliant substrate and the free-standing substrate is due to the interaction of the misfit dislocation with the dislocation arrays in the twist boundary. From the comparison with the experimental observations in the literature, it is shown that the approximation in the present analysis is valid for the compliant substrates with low twist angles. (C) 2000 American Institute of Physics. [S0021-8979(00)04413-3].
Scientific journal, English

Anisotropic stability analysis of surface undulations of strained lattice-mismatched layers
Y Obayashi; K Shintani
THIN SOLID FILMS, ELSEVIER SCIENCE SA, 357, 1, 57-60, Dec. 1999, Peer-reviwed, The anisotropic linear stability analysis of surface undulations in a strained layer on a semi-infinite solid is presented here. The free energy of the system is taken to be the sum of the surface free energy and the elastic strain energy. The calculation is performed under the assumptions that the system is in equilibrium and that the total volume of the system is constant, which correspond to the circumstances in annealing rather than those in crystal growth. Firstly, by estimating the difference between the free energy for the system with a flat surface and the free energy for the system with an undulating surface, we showed that the [100] undulations are more Likely to be formed than the [100] undulations. Secondly, we compared the critical layer thickness for misfit dislocation formation with the layer thickness range where surface undulations always decay. Numerical results for the Si(1-x)Ge(x)/Si systems show that misfit dislocation generations tend to occur for x < 0.5 and surface undulations do for x > 0.5. These tendencies are in agreement with the experimentally observed features of surface morphology in the literature. (C) 1999 Elsevier Science S.A. All rights reserved.
Scientific journal, English

Anisotropic stability analysis of surface undulations of strained lattice-mismatched layers
Y. Obayashi; K. Shintani
Materials Research Society 1998 Fall Meeting, Abstracts, 43-(発表番号J3.4), 02 Dec. 1998, Peer-reviwed, The dependence of the surface morphological instability on the direction of a sinusoidal surface undulation in a coherent heteroepitaxial layer is investigated under the condition of constant volume of material. Numerical results show that in a Si_{1-x}Ge_{x} structure, the critical wave length for <100> surface undulations is smaller than that for <110> surface undulations and that the critical wave length decreases with the increase of Ge fraction. It is also shown that the growth rate of the amplitude takes the maximum when the wavelength is 4/3 times the critical wavelength, even if anisotropy is taken into account.
International conference proceedings, English

Directional dependence of surface morphological stability of heteroepitaxial layers
Y Obayashi; K Shintani
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 84, 6, 3141-3146, Sep. 1998, Peer-reviwed, Surface morphological stability in coherent heteroepitaxial layers is analyzed focusing on the directional dependence of surface undulations created by surface diffusion. The critical stability condition is defined in terms of the free energy of the system which is assumed to be the sum of the elastic strain energy and the surface free energy. The displacement and stress fields of the semi-infinite anisotropic solid with the slightly undulating surface are calculated by using the surface admittance tensor and the vector complex potential function. Numerical results for the Si(1-x)Ge(x)/Si systems show that the critical wavelength of the [100] surface undulations is smaller than that of the [110] surface undulations, which means that surface undulations are likely to be formed in the [100] directions. It is also found that the critical wavelength decreases with the increase of Ge fraction. These tendencies are in good agreement with the observations in annealing experiments for the Si(1-x)Ge(x)/Si systems in the literature. If the substrate is assumed to be rigid, the range of layer thickness where the system is absolutely stable against a surface undulation of any wavelength exists. Finally, the growth rate of the amplitude of surface undulations is estimated from an evolution equation for the surface shape. It is shown that even if anisotropy is taken into account, the growth rate of the amplitude takes the maximum value when the wavelength is 4/3 times the critical wavelength, which is the same as in the isotropic approximation. (C) 1998 American Institute of Physics.
Scientific journal, English

Is the Hagen-Strunk multiplication mechanism of misfit dislocations in heteroepitaxial layers probable?
Y. Obayashi; K. Shintani
Philosophical Magazine Letters, 76, 1, 1, Jul. 1997, Peer-reviwed
Scientific journal, English

Elementary interaction characteristics of dislocations at the nucleation, extension, and multiplication in strained epitaxial layers
K. Shintani; Y. Maeda; Y. Obayashi
XIXth International Congress of Theoretical and Applied Mechanics, Abstracts, 755, Aug. 1996, Peer-reviwed, Elementary interactions of three different configurations of dislocations in strained epitaxial layers are analytically investigated taking image stresses into account. Double surface half-loops, two angular dislocations, and crossing and annihilating misfit dislocations observed in the nucleation, extension, and multiplication of dislocations, respectively, are considered. The numerical results show that the interaction energy of a double half-loop is negative and the total free energy of the system decreases when the two surface half-loops are in close proximity, interaction between two angular dislocations at the distance of the same order of layer thicknesse in the same glide plane reduces the critical layer thickness by 10 to 25% of the Matthews-Blakeslee critical thickness, and there exists another critical layer thickness at which the total force exerted on the inclined segments of two crossing and annihilated misfit dislocations becomes zero and no more multiplications occur.
International conference proceedings, English

Interaction characteristics of dislocations in strained epitaxial layers
K Shintani
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 79, 1, 179-183, Jan. 1996, Peer-reviwed, In connection with nucleation and multiplication processes of misfit dislocations in epitaxial layers, elastic interactions of some configurations of dislocation surface half-loops and angular dislocations are investigated. By using the programme code produced by Gosling and Willis [J. Mech. Phys. Solid 42, 1199 (1994)], which calculates the image stresses of a straight dislocation half-line in a half-space and enables one to construct the stress field of any configuration of dislocation loops, the interaction energy of two surface half-loops is obtained. With the change of the relative positions of the two half-loops, the;sign of the interaction energy varies from minus to plus, in accordance with which the interaction force between the two half-loops varies from an attractive force to a repulsive one. The interaction forces exerted on threading segments are also estimated for two angular dislocations, and their effects on the Matthews and Blakeslee equilibrium are discussed. (C) 1996 American Institute of Physics.
Scientific journal, English

COMPARATIVE-STUDY OF CRITICAL THICKNESSES OF STRAINED EPITAXIAL LAYERS BASED ON THE ZERO-ENERGY CRITERION OF DISLOCATION HALF-LOOPS
K SHINTANI; H YONEZAWA
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 78, 8, 5022-5027, Oct. 1995, Peer-reviwed, Considering nucleation of dislocation half-loops from the crystal growth surface as a mechanism of generation of misfit dislocations between an epitaxial film and a substrate, critical thicknesses can be determined by calculating the zero of free energy of the system according to van de Leur et al.'s model [J. Appl. Phys. 64, 3043(1988)]. On estimating the free energy, two analytical methods are adopted; one is the whole-space approximation and another treats surface half-loops in the half-space by the image stress construction. In both of the methods, interaction between the two dislocation glide loops either lying in the identical slip plane or lying in the parallel slip planes are incorporated into the analysis. It is shown that half-loop correction reduces critical thickness, the former interaction reduces and the latter interaction increases it, and the interaction effects become smaller by the half-space correction. Finally it is also shown that the effect of anisotropy in the whole-space approximation tends to increase critical thickness. (C) 1995 American Institute of Physics.
Scientific journal, English

CONDUCTION-CONTROLLED DISPERSION OF SURFACE ACOUSTIC-WAVES IN III-V AND II-VI COMPOUND SEMICONDUCTORS - THE EFFECT OF DRIFT CURRENT
K SHINTANI; H ITOH
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE, PERGAMON-ELSEVIER SCIENCE LTD, 32, 8, 1271-1276, Aug. 1994, Peer-reviwed, A formulation for analyzing surface acoustic waves in piezoelectric semiconductors is given based on Maxwell's equations; drift current is taken into account, diffusion current being neglected. Dispersion curves are obtained for the surface acoustic waves in GaAs, ZnO, and CdS. It is seen that simple relaxation-type dispersions occur around dielectric relaxation frequencies in the same way as for plane waves.
Scientific journal, English

Effect of anisotropy on the excess stress and critical thickness of capped Si_1-x_Ge_x_ strained layers
K. Shintani; K. Fujita
Journal of Applied Physics, 75, 12, 7842-7846, Jun. 1994, Peer-reviwed
Scientific journal, English

DISLOCATION BENDS IN PIEZOELECTRIC MATERIALS
K SHINTANI
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 73, 10, 4794-4796, May 1993, Peer-reviwed, It is shown that J. Lothe's theorem [Philos. Mag. 15, 353 (1967)] is also valid for piezoelectric materials by replacing the energy factor. Its proof follows L. M. Brown's procedure [Philos. Mag. 15, 363 (1967)]. The forces on dislocation bends in lithium niobate are numerically calculated.
Scientific journal, English

LINE TENSION AND CONFIGURATION OF A DISLOCATION ON THE BASAL, PRISMATIC, AND PYRAMIDAL PLANES IN ZINC-OXIDE
K SHINTANI
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 47, 12, 7032-7035, Mar. 1993, Peer-reviwed, The line tension and equilibrium configuration of a planer-dislocation shear loop on the basal, prismatic, and pyramidal planes in zinc oxide under an external stress are calculated. An extended version of the formulation of deWit and Koehler applicable to piezoelectric crystals is used, and the piezoelectric effects on the line tension and configuration are estimated. The results for zinc oxide are compared with those for zinc, and the characteristic features of zinc oxide are discussed.
Scientific journal, English

EQUILIBRIUM SHAPES OF DISLOCATION SHEAR LOOPS IN LITHIUM-NIOBATE AND LITHIUM TANTALATE UNDER AN EXTERNAL STRESS IN THE LINE TENSION APPROXIMATION
K SHINTANI
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, TAYLOR & FRANCIS LTD, 67, 2, 361-368, Feb. 1993, Peer-reviwed, The line tension approximation method developed by DeWit and Koehler in 1959 is applied to the calculation of equilibrium shapes of planar dislocation loops in piezoelectric crystals under an external stress. The self-energy expression is derived from the solutions for the stress and electric fields around a straight dislocation. Numerical results are displayed for lithium niobate and lithium tantalate.
Scientific journal, English

On the equilibrium shape of a dislocation in piezoelectric crystals
K. Shintani; S. Minagawa
International Symposium on Nonlinear Phenomena in Electromagnetic Fields, Abstracts, 105, Jan. 1992, Peer-reviwed, The method of DeWit and Koehler for calculating the equilibrium shape of a curved dislocation is extended to the case of a dislocation in a piezoelectric crystal, and the effect of the electric field around the dislocation is examined. The expression for the self energy of a charged dislocation in a piezoelectric crystal previously obtained by the authors is applied.
International conference proceedings, English

SCREENED POTENTIAL OF A CHARGED DISLOCATION IN PIEZOELECTRIC SEMICONDUCTORS
K SHINTANI
JOURNAL OF APPLIED PHYSICS, AMER INST PHYSICS, 69, 12, 8119-8121, Jun. 1991, Peer-reviwed, A simplified model is proposed for analyzing the electric potential around a charged dislocation in piezoelectric semiconductors. In the analysis of the order of the Debye length, the solution for the piezoelectric potential screened by the carriers and ionized impurities is obtained. Consideration of the electrostatic potential field near the dislocation complete the determination of the solution. Numerical calculations of the potential are made for GaAs.
Scientific journal, English

Effects of carriers on the electric fields around dislocations in piezoelectric semiconductors
K. Shintani
International Symposium on the Application of Electromagnetic Forces, Abstracts, 175, Jan. 1991, Peer-reviwed, A model is presented for analyzing the screening effects of carriers on the electric field around a straight dislocation under the formulation of Merten and Saada. Since piezoeletric linear constitutive equations and solutions for the stress field derived using the elasticity theory no longer hold in the neighborhood of the dislocation core, the solution mast be sought by dividing the space around the dislocation into two parts; one is of the order of the radius of the core and the other is of the order of Debye length.
International conference proceedings, English

Dislocation dynamics in anisotropic piezoelectric crystals III. Elliptical dislocation loop
K. Shintani; S. Minagawa
Philosophical Magazine A, 62, 3, 275-282, Sep. 1990, Peer-reviwed
Scientific journal, English

ON SOME PROBLEMS IN THE MICROMECHANICS OF DEFECTS IN AN ELECTROMAGNETIC SOLID
S MINAGAWA; K TOMIZAWA; K SHINTANI
MECHANICAL MODELLINGS OF NEW ELECTROMAGNETIC MATERIALS, ELSEVIER SCIENCE PUBL B V, 89-94, 1990, Peer-reviwed, The formula for the mechanical and electrical fields produced by a continuous distribution of moving dislocations in an anisotropic piezoelectric crystal are extended to incorporate the electric charges of dislocation cores. As numerical examples, the stress and electric fields around an infinite straight dislocation in GaAs are shown, and its self energy and the interaction energy between the two parallel dislocations are calculated.
International conference proceedings, English

Analysis of electric fields due to a moving dislocation loop in anisotropic piezoelectric crystals
K. Shintani; S. Minagawa
Applied Electromagnetics in Materials, Pergamon, 337-343, 1989, Peer-reviwed, The mathematical procedure for analyzing the electric fields produced by a moving dislocation loop in anisotropic piezoelectric crystals is summarized. Numerical results are shown for a circular dislocation loop wich moves uniformly in GaAs.
International conference proceedings, English

FIELDS OF DISPLACEMENT AND ELECTRIC-POTENTIAL PRODUCED BY MOVING DISLOCATIONS IN ANISOTROPIC PIEZOELECTRIC-CRYSTALS
K SHINTANI; S MINAGAWA
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE, PERGAMON-ELSEVIER SCIENCE LTD, 26, 8, 893-901, 1988, Peer-reviwed
Scientific journal, English

REVERSIBLE GENERATIONS OF HEAT CAUSED BY MOVING DISLOCATIONS IN A COUPLED-THERMOELASTIC SOLID WITH THERMAL-CONDUCTIVITY
S MINAGAWA; RKT HSIEH; JP NOWACKI; K SHINTANI
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE, PERGAMON-ELSEVIER SCIENCE LTD, 26, 11, 1169-1175, 1988, Peer-reviwed
Scientific journal, English

Dislocation dynamics in anisotropic piezoelectric crystals II. Additional examples
S. Minagawa; K. Shintani
Philosophical Magazine A, 56, 3, 343-352, Sep. 1987, Peer-reviwed
Scientific journal, English

DISLOCATION DYNAMICS IN ANISOTROPIC PIEZOELECTRIC-CRYSTALS
S MINAGAWA; K SHINTANI
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, TAYLOR & FRANCIS LTD, 51, 2, 277-285, 1985, Peer-reviwed
Scientific journal, English

Low Reynolds number flow past a flat Plate
K. Shintani
Theoretical and Applied Mechanics, 32, 73-78, 1984, Peer-reviwed
Scientific journal, English

LOW-REYNOLDS-NUMBER FLOW PAST AN ELLIPTIC CYLINDER
K SHINTANI; A UMEMURA; A TAKANO
JOURNAL OF FLUID MECHANICS, CAMBRIDGE UNIV PRESS, 136, NOV, 277-289, 1983, Peer-reviwed
Scientific journal, English

Theoretical analysis of the interaction between two burning fuel droplets (Part I: Identical droplet case)
A. Umemura; S. Ogawa; N. Oshima; K. Shintani
Bulletin of the Japan Society of Mechanical Engineers, 23, 186, 2071-2075, Dec. 1980, Peer-reviwed
Scientific journal, English

Effective thermal conductivity of spheres in slow flows
K. Shintani; N. Oshima
Journal of the Faculty of Engineering, The University of Tokyo (B), 35, 3, 455-463, 1980, Peer-reviwed
Research institution, English

Drag of parallel cylinders in slow flow
T. Kato; K. Shintani; S. Ogawa; N. Oshima
Theoretical and Applied Mechanics, 28, 411-419, 1980, Peer-reviwed
Scientific journal, English

Nanomechanics by means of molecular-dynamics simulation
K. Shintani
Oct. 2004, Materials Science and Technology, 41, 5, 234-239, Japanese, Peer-reviwed, Introduction other

Reduction of the Thermal Conductivity of Bilayer Graphene via Interlayer sp3 Bonds
T. Iwata; K. Shintani
Oral presentation, Japanese, 2018 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Yokohama, 二層グラフェンに規則的配置と不規則配置の二種類のsp3層間結合を広い範囲の分率で導入した場合にその熱伝導度がどのように変化するかを調べた．, Domestic conference
31 May 2018

Molecular Dynamics of Carbon Materials
K. Shintani
Invited oral presentation, Japanese, 2018 Annual Meeting of the Materials Science Society of Japan, Invited, Materials Science Society of Japan, Yokohama, 種々のPAHのCNT内包過程と内部積層構造の形態を分子動力学（MD）法によって調べた結果をレヴューした．また，二層グラフェンの間にsp3層間結合を人為的に挿入してその熱伝導度を低減させる方法がグラフェン/hBNヘテロ二層に対しても有効であることを示した．, Domestic conference
31 May 2018

Sharp fall of the thermal conductivity of a van der Waals heterobilayer due to interlayer sp3 bonds
T. Iwata; K. Shintani
Poster presentation, English, European Conference on Nanofilms 2018, hosted by the ecnf2018 conference committee and recognized by European Materials Research Society., Cranfield University, http://www.ecnf2018.org/, Sharp decrease and existence of the minimum of the thermal conductivity (TC) of a graphene/hexagonal boron nitride (hBN) heterobilayer due to interlayer sp3 bonds are demonstarted via nonequilibrium molecular dynamics simulation. Since interlayer sp3 bonds act as phonon scatterers, the TC sharply falls if there are a small number of them. As their number increases, their role as a fastener of the two layers becomes more and more significant, as a result of which the heterobilayer becomes a quasi three-dimensional structure and its TC begins to increase again. This is confirmed by examining the phonon density of states (DOSs) in the heterobilayer with/without interlayer sp3 bonds., International conference
22 Mar. 2018

Encapsulation of pyrenes into a carbon nanotube and formation of their stacking structure
佐々木遼; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第24期総会・講演会講演論文集, Japan Society of Mechanical Engineers, Tokyo, https://www.jsme.or.jp/conference/ktconf18/, Dynamic encapsulation of pyrenes into a single-walled carbon nanotube (SWCNT) is addressed via molecular dynamics (MD) simulation. It is revealed the final structures of encapsulated pyrenes are classified into two categories according to the magnitude of the SWCNT diameter. For the SWCNT diameters less than 1.470 nm, the azimuthal angles of pyrenes during sliding within the SWCNT are almost zero, and they form a stack, whereas for the SWCNT diameters equal to or greater than 1.470 nm, their azimuthal angles during sliding are nonzero, and they form not a stack but a sequence of trimers. The conjugate-gradient (CG) energy minimization confirms the final stacking structures for the SWCNT diameters less than 1.470 nm obtained via MD are energetically favorable ones. A semi-analytical formula expresses well the tilt angles obtained via MD., Domestic conference
18 Mar. 2018

Dynamic Encapsulation of Polycyclic Aromatic Hydrocarbons into Carbon Nanotubes
R. Sasaki; K. Shintani
Poster presentation, English, 2017 Materials Research Society Fall Meeting, Materials Research Society, Hynes Convention Center and Sheraton Boston Hotel, Boston, Massachusetts, U. S. A., http://www.mrs.org/fall2017, Pyrene is a rhombic-shaped flat polycyclic aromatic hydrocarbon molecule with blue fluorescence property. If pyrenes are encapsulated into a single-walled carbon nanotube (SWCNT), the resulting hybrids might be fluorescent probes for diseased sites in organisms. In this paper, dynamic encapsulation of pyrenes into a SWCNT is simulated using molecular dynamic method. If an edge-opened SWCNT is inserted into an equilibrated pyrene atmosphere, spontaneous encapsulation of pyrenes into the SWCNT starts and continues until the SWCNT is filled with pyrenes. The encapsulated pyrenes are deformed to be of the shape of saddle and inevitably form their dimers with their faces parallel to the SWCNT inner wall. After the SWCNT is filled with such dimers, they start to make angles with the SWCNT axis sequentially from the end of the SWCNT where additional pyrenes enter the SWCNT. The tilt angles of the stacked pyrenes are calculated, and their dependences on the SWCNT diameter are expressed by a semi-analytical formula useful for controlling the morphologies of the stacked molecules., International conference
28 Nov. 2017

Thermal Properties of a Graphene/Hexagonal Boron Nitride Heterobilayer with Interlayer Bonds
T. Iwata; K. Shintani
Poster presentation, English, 2017 Materials Research Society Fall Meeting, Materials Research Society, Hynes Convention Center and Sheraton Boston Hotel, Boston, Massachusetts, U. S. A., http://www.mrs.org/fall2017, A graphene/hexagonal boron nitride (hBN) heterobilayer (HBL) is among two-dimensional van der Waals heterostructures. In the present paper, the effects of interlayer bonds in a graphene/hBN HBL on its thermal conductivity (TC) are addressed using molecular dynamics (MD) simulation. The TC is estimated by the method of nonequilibrium MD. It is shown that the TC of a graphene/hBN HBL sharply decreases if only a few interlayer bonds exist, and continues to gradually decrease with increasing the density of the interlayer bonds up to about 25 %. However, it starts to gradually increase if the density of the interlayer bonds exceeds about 25 %. Namely, there exists a minimum TC of the HBL. The reduction of the TC occurs because the interlayer bonds work as phonon scatterers. On the other hand, its increase occurs because the rigidity of the HBL is enhanced via interlayer bonds. Its minimum appears resulting from the balance between the both actions of the interlayer bonds. In order to confirm such an interpretation, the phonon density of states (DOSs) in the HBLs with/without interlayer bonds are examined in details., International conference
28 Nov. 2017

Gas separation properties of graphene with nanopores
Hakuyo Katsu; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 30th Conference of the JSME Computational Mechanics Division (CMD2017), Japan Society of Mechanical Engineers, Higashiosaka-shi, https://www.jsme.or.jp/cmd/conference/cmdconf17/, Gas separation using membrane consumes small energy and is important in the development of clean technology. In recent years, graphene with nanopores has attracted attention as a gas separation membrane. In this study, the usefulness of graphene with nanopores in hydrogen separation from mixed gases is shown, and the mechanism of separation and permeation is revealed. It turned out that there is a big difference in the way gas molecules enter the pores, depending on the shapes of the pores., Domestic conference
17 Sep. 2017

Thermal and mechanical properties of atomic-layer materials with interlayer bonds
Takuya Iwata; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 30th Conference of the JSME Computational Mechanics Division (CMD2017), Japan Society of Mechanical Engineers, Higashiosaka-shi, https://www.jsme.or.jp/cmd/conference/cmdconf17/, The performance index of the Seebeck effect is inversely proportional to the thermal conductivity. Hence, a material with low thermal conductivity can be used as a highly efficient thermoelectric conversion material. In this study, we investigate the influence of the density of interlayer bonds on the thermal conductivity and mechanical properties of a hetero-bilayer structure consisting of graphene and hexagonal boron nitride (hBN). It is found that its thermal conductivity gradually decreases with increasing the density of interlayer bonds. By calculating the local phonon density of states (DOS) and examining the overlapped energy of the phonon DOS, we discuss the mechanism of the decrease of the thermal conductivity., Domestic conference
17 Sep. 2017

Do corannulene molecules make a stack in a carbon nanotube?
Y. Joko; R. Sasaki; K. Shintani
Poster presentation, English, AEM2017 (10th International Conference on Advanced Nano materials), AEM2017 Committees, University of Surrey, Guildford, Surrey GU2 7XH, UK, http://www.aem2017.com/, The usage of a carbon nanotube (CNT) as a template in which polycyclic aromatic hydrocarbon (PAH) molecules, coronene, sumanene, corannulene, etc. are stacked is an example of its indirect application. Although the energetics of corannulene molecules in a SWCNT was discussed in the literature, dynamical encapsulation of them into a SWCNT has not been studied yet, and whether they are orderly stacked or not is still an open question. In the present paper, an effort to answer this question is made. It is revealed corannulnes tend to form an ordered stack or a partially ordered stack, and its structural motif is CC dimers., International conference
12 Sep. 2017

Simulation of a carbon nanotube encapsulating polycyclic aromatic hydrocarbon
Ryo SASAKI; Kazuhito SHINTANI
Oral presentation, Japanese, Mechanical Engineering Congress, 2017 Japan (MECJ-17), Japan Society of Mechanical Engineers, Saitama, 多環芳香族炭化水素(PAH)雰囲気中のカーボンナノチューブ(CNT)には、PAH分子が内包されその積層構造が形成される。本研究では、PAH分子の一種であるピレン雰囲気中に置かれたCNTへのピレン分子の内包過程とその積層構造を分子動力学法によって調べた。さらに、ピレンとコロネンの混合雰囲気中に置かれたCNTへのピレンとコロネンの内包過程とその積層構造についても調べた。その結果、ピレン雰囲気からの内包ではピレンはCNT内部でダイマーを形成しつつ積層構造を形成すること、また、ピレンとコロネンの混合雰囲気からの内包では、ピレンとコロネンがそれぞれの集合体となって積層構造を形成することが分かった。, Domestic conference
04 Sep. 2017

Dynamic encapsulation of bowl-shaped π-conjugated molecules into single-walled carbon nanotubes
K. Mouri; Y. Joko; R. Sasaki; K. Shintani
Invited oral presentation, English, JKMST2017(The 4th Japan-Korea International Symposium on Materials Science and Technology 2017) ABSTRACT, Invited, The Materials Science Society of Japan/Materials Research Society of Korea, Higashiosaka-shi, Osaka, It was experimentally shown that polycyclic aromatic hydrocarbon (PAH) molecules spontaneously enter edge-opened carbon nanotubes (CNTs) to form hybrid structures PAHs@CNTs if the CNT are exposed to PAH atmospheres [1]. PAHs may hold their original electronic and optical properties after encapsulation depending on their morphologies in CNTs. Coronene is a flat molecule while sumanene and corannulene are bowl-shaped fragments of a fullerene. In this paper, dynamic encapsulation of sumanenes/corannulenes into a single-walled CNT (SWCNT) is studied using molecular dynamics simulation. It is revealed that sumanenes/corannulenes enter the host SWCNT with their planes parallel to the SWCNT axis, and tend to make their concave-concave dimers [2]. When the SWCNT is filled with the encapsulated molecules, these dimers assemble to make their stacks or are arranged such that their convex surfaces face the inner wall of the host SWCNT. The tilt angles of the molecules decrease with increasing the SWCNT diameter. The dependences of the tilt angles on the SWCNT diameter are successfully expressed by semi-analytical formulas which are derived on the geometrical constraint condition., International conference
25 Aug. 2017

Encapsulation of polycyclic aromatic hydrocarbons into carbon nanotubes and their stacking morphologies depending on molecular shape
R. Sasaki; Y. Joko; K. Mouri; K. Shintani
Oral presentation, Japanese, The 64th National Congress of Theoretical and Applied Mechanics, Science Council of Japan, Minato-ku Tokyo, If edge-opened carbon nanotubes (CNTs) are inserted into polycyclic aromatic hydrocarbon (PAH) atmosphere, PAH molecules spontaneously enter the CNTs and tend to create their stacks. In this paper, encapsulation of coronenes, sumanenes, and corannulenes into a CNT is studied using molecular dynamics simulation. We discuss how these PAH molecules create their stacks, how the tilt angles of the stacks depend on the CNT diameter, and how their stacking morphologies depend on their molecular geometries. Since coronene is a planar molecule whereas sumanene and corannulene are bow-shaped molecules, their stacks have the geometrical characteristics according to their molecular shapes., Domestic conference
24 Aug. 2017

Simulation of Encapsulation of PAH Molecules into Nanotubes
Y. Joko; R. Sasaki; K. Shintani
Oral presentation, Japanese, 2017 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Yokohama, 開口端カーボンナノチューブ（CNT)が多環芳香族炭化水素（PAH)雰囲気中に置かれると、PAH分子は自発的にCNTに内包される。本研究では、分子動力学シミュレーションによって、多環芳香族炭化水素の一種であるコラヌレン分子の内包シミュレーションを行った。その結果、以下の結論を得た。コラヌレン分子はCNTに自発的に内包される。CNTの直径が小さい場合には、コラヌレン分子面がCNT軸に平行な凹凹ダイマー列を形成する。CNTの直径が大きい場合には、CNT軸と角度をなす凹凹ダイマーが積層する。後者の場合、その傾斜角は幾何学的拘束によって決まり、CNTの直径をアーギュメントとする余弦の逆関数によって表すことができる。, Domestic conference
26 Jun. 2017

Encapsulation of PAH molecules and their stacked structures in a carbon nanotube
上甲優介; 佐々木 遼; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第23期総会・講演会, Japan Society of Mechanical Engineers, Tokyo, If carbon nanotubes (CNTs) are inserted in an atmosphere of polycyclic aromatic hydrocarbon (PAH) molecules, the PAH molecules spontaneously enter into the CNTs and form stacked structures within the CNTs. The structural morphology of the stacked PAH molecules depends on the CNT diameter. In this report, encapsulation of corannulene molecules into a single-walled CNT (SWCNT) is studied. Firstly, their minimum-energy structures in a SWCNT are obtained by conjugate-gradient (CG) minimization. Secondly, encapsulation of corannulene molecules into a SWCNT is simulated by means of molecular-dynamics (MD). The tilt-angle of the stacked corannulene molecules is calculated both from the minimum-energy structures via CG and from the final structures via MD, and how the tilt-angle varies with the change of the CNT diameter is investigated., Domestic conference
17 Mar. 2017

Analysis of the mechanical and thermal properties of graphene with grain boundaries
山崎彰太; 岩田拓也; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第23期総会・講演会, Japan Society of Mechanical Engineers, Tokyo, The thermal conductivity (TC) of graphene is so large that it is applicable to thermal treatment in electronic devices. However, the TC of the graphene grown by chemical vapor deposition is lower than the TC of pristine graphene because the former is polycrystalline. The scattering of phonons at the grain boundaries (GBs) reduces the TC of the polycrystalline graphene. In this report, the TC of a graphene nanoribbon (GNR) with a GB is investigated by means of nonequilibrium molecular-dynamics. A GB is expressed in terms of an alternate sequence of five- and seven-membered rings of carbon atoms which is situated along the center line in a rectangular GNR. At an edge of the GNR in the direction normal to the GB, heat q per unit time is added, whereas at another end of the GNR, heat q per unit time is removed. The MD is performed until the steady temperature distribution is constructed. The inverse of the effective TC is obtained by summing the inverses of the TCs of the non-defective areas and the inverse of the product of the characteristic grain length and the Kapitza conductance at the GB. The result is compared with the TC of pristine graphene., Domestic conference
17 Mar. 2017

Stacking of Polycyclic Aromatic Hydrocarbon Molecules Encapsulated in a Single-Walled Carbon Nanotube
K. Mouri; K. Shintani
Poster presentation, English, 2016 Materials Research Society Fall Meeting, Materials Research Society, Boston, One of the possible applications of single-walled carbon nanotubes (SWNTs) is their use as templates or containers to encapsulate polycyclic aromatic hydrocarbon (PAH) molecules, viz., coronene, perylene, sumanene, etc. Recent researches to aim at such applications are divided into the two directions; one is to synthesize graphene nanoribbons (GNRs) via fusion of PAH molecules, and another is to stack PAH molecules under van der Waals interactions. Okazaki et al. (2011) observed self-organized columnar stacks of coronene molecules within SWNTs through vapor-phase doping. In this paper, we study the morphology of coronene molecules encapsulated in a SWNT by means of molecular-dynamics simulation. Edge-opened SWNTs of various diameters are placed in a coronene atmosphere, and the dynamical process of encapsulation of coronene molecules into SWNTs is followed. The resulting stacking morphologies of the encapsulated molecules are examined; how the tilt angles and inter-molecular distances of the columnar stacks depend on the diameter of the SWNTs is shown. The geometrical constraint condition for columnar stacks of coronene in SWNTs is discussed., International conference
28 Nov. 2016

Analysis of the mechanical properties of a pillared-graphene nanostructure
Ryo SASAKI; Kazuhito SHINTANI
Oral presentation, Japanese, Mechanical Engineering Congress, 2016 Japan (MECJ-16), Japan Society of Mechanical Engineers, Fukuoka, Kondo et al. (2008)はグラフェンの平面に対してカーボンナノチューブ (CNT) が垂直に接合したナノカーボン複合構造体である支柱型グラフェンを実験的に合成することに成功した。本研究では支柱型グラフェンのインデンテーションシミュレーションを行い、その硬さを調べた。, Domestic conference
13 Sep. 2016

Structural analysis of a sumanene stack within a carbon nanotube
Keiichiro MOURI; Kazuhito SHINTANI
Oral presentation, Japanese, Mechanical Engineering Congress, 2016 Japan (MECJ-16), Japan Society of Mechanical Engineers, Fukuoka, コロネン、スマネンは多環芳香族炭化水素(PAH)の一種である。コロネンの重合反応によりダイコロニレンやグラフェンナノリボン(GNR)などの合成が可能である。スマネンは 2003 年に平尾、桜井らにより初めて合成されたお椀の形状をした分子であり、センサーや分子マシンのユニットとしての応用が期待されている。また、Okazaki et al. (2011) の実験によれば、コロネンはカーボンナノチューブ(CNT)に内包されると積層構造をとることがわかっている。本計算では、コロネンとスマネンの CNT への内包の過程と構造を解析する。, Domestic conference
13 Sep. 2016

Analysis of the mechanical properties of rebar graphene via nanoindentation
H. Katsu; K. Shintani
Poster presentation, Japanese, 2016 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 多結晶グラフェンの強度特性の向上を目指して、多結晶グラフェンの粒界上にカーボンナノチューブ（CNT)を配置した複合構造をリーバーグラフェンと称する。本研究では、分子動力学法によってリーバーグラフェンのインデンテーションシミュレーションを行って、荷重‐たわみ曲線に及ぼすCNTの効果を調べた。その結果、CNTの存在により強度特性の向上を確認した。, Domestic conference
29 Jun. 2016

Analysis of thermal rectification of graphene nanoribbon with an asymmetric geometry
T. Iwata; K. Shintani
Poster presentation, Japanese, 2016 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 中央にテーパー部分を有するグラフェンナノリボン（GNR）の熱電導度を非平衡分子動力学シミュレーションによって求めた。その結果、熱伝導度が熱流方向によって異なるという熱整流特性が確認できた。そのメカニズムは、GNRエッジ部分のフォノン散乱によって説明できる。, Domestic conference
29 Jun. 2016

Analysis of the formation and structure of a coronene stack in a carbon nanotube
毛利 慧一郎; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第22期総会・講演会, 日本機械学会, 東京, Domestic conference
10 Mar. 2016

Analysis of the mechanical properties of a pillared-graphene nanostructure
佐々木 遼; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第22期総会・講演会, 日本機械学会, 東京, Domestic conference
10 Mar. 2016

Analysis of the mechanical properties of rebar graphene
山崎彰太; 新谷一人
Oral presentation, Japanese, 日本機械学会2015年度年次大会, 日本機械学会, 札幌, Nanoscale hybrids attract much attention of researchers nowadays. Rebar graphene is one of such hybrids. It means polycrystalline graphene which is reinforced by carbon nanotubes laid across its grain boundaries. In this paper, the tensile properties of rebar graphene are investigated by means of molecular-dynamics. Simulation models consist of rectangular twinning graphene and carbon nanotubes. The effects of the number and length of reinforcing carbon nanotubes on the strength of rebar graphene are examined., Domestic conference
14 Sep. 2015

Simulation of filling of coronene molecules into carbon nanotubes
阪根 嘉成; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第21期総会・講演会, 日本機械学会, 横浜, Domestic conference
20 Mar. 2015

Analysis of the electronic properties of transition metal chalcogenides
杉本 淳; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第21期総会・講演会, 日本機械学会, 横浜, Domestic conference
20 Mar. 2015

Analysis of the thermal properties of nanocarbon hybrids
利府 学; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第21期総会・講演会, 日本機械学会, 横浜, Domestic conference
20 Mar. 2015

Analysis of the thermal properties of pillared-graphene nanostructures
利府 学; 新谷一人
Oral presentation, Japanese, 日本機械学会第27回計算力学講演会(CND2014)講演論文集, 日本機械学会, 盛岡, Domestic conference
22 Nov. 2014

Formation process of coronene-encapsulating carbon nanotubes
阪根 嘉成; 新谷一人
Oral presentation, Japanese, 日本機械学会第27回計算力学講演会(CND2014)講演論文集, 日本機械学会, 盛岡, Domestic conference
22 Nov. 2014

First-Principles Structural Analysis of Vacancy Defects in Graphene
杉本 淳; 新谷一人
Oral presentation, Japanese, 日本機械学会2014年度年次大会, 日本機械学会, 東京, Graphene grown on substrates ordinarily have defects in its structure. Such defects affect the electronic properties of graphene. In this report, the atomic structures of graphene having a monovacancy or a multivacancy are equilibrated using first-principles calculations. The formation energies and bandgaps of the equilibrated structures are compared with each other. It is shown that the formation energy of a 555-777 divacancy is the lowest, and that graphene with some kinds of
defects can have nonzero bandgaps.
08 Sep. 2014

Analysis of the mechanical properties of polycrystalline graphene under tensile loads
青木佑介; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第20期総会・講演会講演論文集 No. 140-1, 日本機械学会, 東京, Domestic conference
15 Mar. 2014

First-principles calculation for group-IV graphane-like nanomaterials
三原紘大; 新谷一人
Oral presentation, Japanese, 日本機械学会関東支部第20期総会・講演会講演論文集 No. 140-1, 日本機械学会, 東京, Domestic conference
15 Mar. 2014

Interaction between a Single-Walled Carbon Nanotube and an Encapsulated Graphene Nanoribbon
F. Furuhashi; K. Shintani
Oral presentation, English, 2013 Materials Research Society Fall Meeting, Materials Research Society, Boston, International conference
03 Dec. 2013

Strength analysis of polycrystalline graphene
青木佑介; 新谷一人
Oral presentation, Japanese, 日本機械学会第26回計算力学講演会講演論文集, 日本機械学会, 佐賀, Domestic conference
03 Nov. 2013

First-principles calculation of graphene with multivacancies
杉本 淳; 新谷一人
Poster presentation, Japanese, 2013 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, グラフェンは空孔欠陥を有するとそのバンド構造が変化する。本研究では、0～6個の原子が欠損している空孔欠陥を有するグラフェンに対して第一原理計算を行い、安定構造、欠陥生成エネルギー、バンド構造を求め、空孔欠陥が安定構造とバンド構造に及ぼす影響を調べた。その結果、空孔欠陥が直交する2平面に関して鏡面対称で、かつ3回以上の回転対称性を持たない場合に、グラフェンは半導体としてのバンドギャップを有することが分かった。
08 Jun. 2013

Indentation simulation of nanographene
利府 学; 新谷一人
Poster presentation, Japanese, 2013 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法を用いて、単層グラフェンと二層グラフェンのインデンテーションシミュレーションを行い、薄膜の弾性論に基づいて、ヤング率を求めた。その結果、二層グラフェンのヤング率は単層グラフェンのヤング率の半分程度であることが分かった。
08 Jun. 2013

Dynamics analysis of carbon nanobearings
Zaem Arif bin Zainal Abidin; 新谷一人
Poster presentation, Japanese, 2013 Annual Meeting of Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, ナノ機械の研究において、二層カーボンナノチューブ（DWCNT)を用いたベアリングの作製の可能性が提案されている。本研究では、分子動力学シミュレーションによって、DWCNTによって構成されるフランジ付きナノベアリングと段差を有するナノベアリングの動特性を調べた。その結果、フランジ付きナノベアリングは、そのエネルギー散逸が小さく、ナノ機械への応用には有利であることが分かった。, Domestic conference
08 Jun. 2013

Analysis of the electronic properties of g-BC2N on a substrate
A. Saeki; K. Shintani
Oral presentation, Japanese, The 19th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Hachioji, Graphene-like BC2N (g-BC2N) attracts much attention of researchers because of its electronic properties. Since graphene is a good conductor while h-BN is an insulator, the intermediate material of these, g-BC2N, is a simicondutor, and an object of bandgap engineering. In this paper, the ab-initio calculations are performed for two or three sheets of g-BC2N. How their electronic properties depend on the way of stacking is discussed., Domestic conference
16 Mar. 2013

Analysis of the mechanical properties of a pillared-graphene nanostructure under shear loads
H. Sasaki; K. Shintani
Oral presentation, Japanese, The 19th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Hachioji, Molecular dynamics simulations of the shear deformations of a pillared-graphene are performed. This structure consists of two graphene sheets and a carbon nanotube as a pillar between the two sheets. It is revealed that slight anisotropy of the shear stiffness with regards to the shear directions appears, and this anisotropy is due to the atomic structure at the joints of graphene and a carbon nanotube., Domestic conference
16 Mar. 2013

Analysis of morphological properties of graphene on substrates
S. Seto; K. Shintani
Oral presentation, Japanese, 日本機械学会M&M2012材料力学カンファレンスCD-ROM論文集
22 Sep. 2012

Analysis of the mechanical properties of pillared-graphene nanostructures
H. Sasaki; K. Shintani
Oral presentation, Japanese, 日本機械学会M&M2012材料力学カンファレンスCD-ROM論文集
22 Sep. 2012

First principles calculation for carbon nanotubes under torsional deformations
三原紘大; 新谷一人
Poster presentation, Japanese, 2012 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 第一原理計算によって、カイラル指数(5,0)、(5,1)のカーボンナノチューブ（CNT)のねじり変形シミュレーションを行い、バンド構造を計算した。その結果、比ねじり角の増加に伴いバンドギャップが線形に減少することが分かった。, Domestic conference
01 Jun. 2012

Helical structures of a graphene nanoribbon encapsulated in a carbon nanotube
Fumihiro Furuhashi; Kazuhito Shintani
Poster presentation, Japanese, 2012 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, カーボンナノチューブ（CNT)に自発的に内包される有機分子が、CNT内部において重合反応を起こしグラフェンナノリボン（GNR)を形成するという実験結果に基づき、本研究では、分子動力学法により、CNT内部で形成されるGNRの構造をシミュレーションによって求めた。その結果、CNT内部のGNRの形態は、CNT直径とGNRの幅との相対的な関係に支配されていることが分かった。, Domestic conference
01 Jun. 2012

Analysis of the mechanical properties of pillared graphene
Takaaki Hagi; Kazuhito Shintani
Poster presentation, Japanese, 2012 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法により、ピラードグラフェンの引張シミュレーションを行った。その結果、グラフェンとカーボンナノチューブ（CNT)の結合部に応力集中が起こることが分かった。, Domestic conference
01 Jun. 2012

Analysis of the mechanical properties of cross graphene nanoribbons
T. Yoshimura; K. Shintani
Oral presentation, Japanese, The 18th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Narashino, Nanoindentation tests of a cross bar consisting of two grahene nanoribbons (GNRs) are simulated by using molecular dynamics. A carbon nanotube is assumed to be an indenter whose shape is rigidly fixed, and is pushed against the middle of the cross bar. The relationship between the force imposed through the indenter and the deflection of the cross bar is investigated as the size and geometry of the cross bar are changed. The result shows that the force is expressed in terms of the sum of a linear term and a cubic term of the deflection, and such a dependency is consistent with the equation which was obtained experimentally.
10 Mar. 2012

Analysis of the two-dimensional structures of semiconductors by first principles calculation
T. Hanada; K. Shintani
Oral presentation, Japanese, The 18th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Narashino, The electronic properties of SiC nanoribbons are investigated using the first-principles calculation. Their atomic structure is assumed to be the same as the structure of graphene nanoribbons, viz., honeycomb structure. The influences of the width and edge state of the nanoribbons on their density of states and band structure are addressed. The result suggests the bandgap of a SiC nanoribbon depends on the geometry of its stable structure rather than whether it is hydrogen-terminated or not.
09 Mar. 2012

Deformation characteristics of graphene on a substrate
S. Seto; K. Shintani
Oral presentation, Japanese, 日本機械学会2011年度年次大会DVD-ROM論文集
12 Sep. 2011

Stable structure of graphene on SiC
Shoko Seto; Kazuhito Shintani
Poster presentation, Japanese, 日本材料科学会平成23年度学術講演大会講演予稿集, Materials Science Society of Japan, Tokyo, 分子動力学法によって、6H-SiC基板上のグラフェンの形状特性を調べた。その結果、SiC基板に対してグラフェンの角度が0度、30度の傾きを有する場合にグラフェンは最安定構造を有することが分かった。, Domestic conference
03 Jun. 2011

Ab initio calculation of the electronic properties of g-BC_2_N
Ayano Saeki; Kazuhito Shintani
Poster presentation, Japanese, 2011 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, BNCの中で最も安定な組成であるBC2Nに注目し、グラフェンシート状のBC2N（g-BC2N）、グラファイト状のBC2N、ナノリボン状のg-BC2Nに対する第一原理計算を行い、形状の違いによる電子的性質の変化を調べた。その結果、グラファイト状BC2Nは層間距離によらず半導体であること、グラファイト状BC2Nのバンドギャップがg-BC2Nのバンドギャップよりも小さいことが分かった。, Domestic conference
03 Jun. 2011

Molecular-dynamics analysis of coalescence of metal nanoclusters with initial velocities
Takeaki Wakimoto; Kazuhito Shintani
Poster presentation, Japanese, 2011 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, AuクラスターとCuクラスターの合体過程を分子動力学シミュレーションによって追跡した。合体後のクラスターの形態に及ぼす、合体前のクラスターの温度、初速度、サイズを影響を調べた。その結果、合体後のクラスターの形態は合体前のクラスターの初速度に影響を受けないことが分かった。, Domestic conference
03 Jun. 2011

Analysis of the stable structure and electronic properties of bilayer graphene
Hiroki Yamada; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部大17期総会講演会, Japan Society of Mechanical Engineers, Yokohama, In this article, the stable structure of bilayer graphene is obtained by means of molecular dynamics. The band structures of the local parts of such a stable structure are computed by means of first-principles calculation. It is revealed that the magnitude of its band gap is changed by shifting the relative arrangements of the two layers of bilayer graphene., Domestic conference
18 Mar. 2011

Molecular-dynamics of the mechanical properties of one-dimensional nanomaterials
K. Koshiyama; K. Shintani
Oral presentation, Japanese, Proceedings of the 60th Nat. Cong. of Theoretical & Applied Mechanics 2011
10 Mar. 2011

Atomistic study of multi-layered graphene nanobridges
T. Nakajima; K. Shintani
Oral presentation, Japanese, Mechanical Engineering Congress, 2010 Japan (MECJ-10), Japan Society of Mechanical Engineers, Nagoya, The deformation of multilayered graphene nanobribbons (GNRs) both ends of which are fixed is investigated using molecular dynamics simulation. It is found that the total energy of the multilayered GNRs decreases with the increase of the number of layers and tensile strain, and the amplitudes of the out-of-plane deformations of the multilayered GNRs decrease with the increase of the tensile strain., Domestic conference
06 Sep. 2010

Molecular-dynamics analysis of the mechanical properties of metallic-glass nanowires
K. Koshiyama; K. Shintani
Oral presentation, Japanese, Mechanical Engineering Congress, 2010 Japan (MECJ-10), Japan Society of Mechanical Engineers, Nagoya, In this paper, Cu-Zr metallic glass nanowires of amorphous structure are created via the melt-quench simulation based on the molecular dynamics method. The uniaxial tensions are imposed on these nanowires, and the Young's modulus and deformation characteristics are discussed., Domestic conference
06 Sep. 2010

First-principles calculation of the electronic characteristics of graphene
Toshimasa Hanada; Kazuhito Shintani
Poster presentation, Japanese, 2010 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, グラフェンシートとグラフェンナノリボン（GNR)の第一原理計算を行い、安定構造と電子状態を求めた。その結果、GNRの幅が大きくなるにつれてバンドギャップが小さくなること、エッジがジグザグ方向であるGNRは半金属的なバンド構造を有することが分かった。, Domestic conference
04 Jun. 2010

Molecular dynamics analysis of nanoindentation of graphene
Tomohiro Yoshimura; Kazuhito Shintani
Poster presentation, Japanese, 2010 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法によって、グラフェンシートのインデンテーションシミュレーションを行った。その結果、グラフェンのヤング率は、0.7～1.01TPaであること、インデンターの大きさがある程度大きくないと正確なヤング率が得られないことが分かった。, Domestic conference
04 Jun. 2010

First-principles calculation of graphene nanoribbons modified by molecules
T. Urakawa; K. Shintani
Oral presentation, Japanese, The 16th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Tokyo, The structural and electronic properties of graphene nanoribbons (GNRs) which are under strain and modifed by H and CO at their edges are investigated by means of first-principles calculation. It is revealed that the geometrical structures and electronic properties of GNRs modified by gas moelcules are affected by strain., Domestic conference
11 Mar. 2010

Molecular dynamics analysis of dynamical behavior of graphene nanoribbons at finite temperatures
T. Nakajima; K. Shintani
Oral presentation, Japanese, The 16th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Tokyo, Edge-constrained graphene nanoribbons (GNRs) of various sizes and initial strains are studied using molecular dynamics simulation. It is revealed that under compressive strain, the out-of-plane deformation of GNRs is caused by buckling, whereas under tensile strain, the out-of-plane deformation of GNRs is caused by ripples and thermal vibrations. It is suggested that the amplitudes of these out-of-plane deformations and ripple patterns are controlled by adjusting their strain., Domestic conference
11 Mar. 2010

Molecular dynamics simulation of carbon nanobearings
K. Sato; K. Shintani
Oral presentation, Japanese, The 16th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Tokyo, Nanoscale bearing structures utilizing nanocarbon materials are proposed based on the prediction via molecular dynamics simulation. The proposed structures consist of a graphene layer, intercalated single-walled carbon nanotubes (SWCNTs), and substrate graphene. It is revealed that the friction against the movement of the uppermost graphene increases with the increase of the number of intercalated SWCNTs., Domestic conference
11 Mar. 2010

Analysis of graphene-supported platinum particles nanocomposites
T. Nakajima; K. Shintani
Oral presentation, Japanese, Mechanical Engineering Congress, 2009 Japan (MECJ-09), Japan Society of Mechanical Engineers, Morioka, Graphene is a single atomic layer of graphite which has two-dimensional honeycomb structure. Although its structure is very simple, graphene has extraordinary physical properties. Its edge has a characteristic configuration called armchair (AC) or zigzag (ZZ). By using molecular-dynamics simulation, it is shown that round and hexagonal flakes of small sizes, the edge configuration influences their energy in equilibrium. Graphene nanoribbons (GNRs) of various aspect rations are equilibrated at low temperature. It is found the energies of equilibrated graphene flakes with ZZ edges are lower than the energies of equilibrated graphene flakes with AC edges. It is also revealed that free graphene flakes undergo compressive edge stress and vibrate at finite temperature, and that a constrained GNR also vibrates., Domestic conference
15 Sep. 2009

Molecular-dynamics analysis of the structure and properties of Ni-Ti nanowires
吉田拓真; 新谷一人
Oral presentation, Japanese, 日本材料科学会平成21年度学術講演大会講演予稿集
05 Jun. 2009

Molecular-dynamics analysis of carbon nanotube oscillators
鐘国志; 新谷一人
Oral presentation, Japanese, 日本材料科学会平成21年度学術講演大会講演予稿集
05 Jun. 2009

First-principles calculations of graphene with defects
T. Kondo; K. Shintani
Oral presentation, Japanese, The 15th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Mito, Graphene is a two-dimensional carbon sheet in which the mobility of electrons is extraordinarily high. In this study, the stable structures, electron density distributions, and band structures of either graphene sheets with Stone-Wales defects or stressed graphene sheets are calculated using first-principles calculations. The differences between the electronic characteristics of unstressed and stressed graphene sheets are discussed., Domestic conference
06 Mar. 2009

Atomistic analysis of coarsening and core-shell mechanisms of metallic nanoparticles via coalescence
S. Mizuno; K. Shintani
Oral presentation, Japanese, The 15th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Mito, Coalescence of two metallic clusters of different elements is studied using molecular-dynamics simulation. All the pair combinations among the six elements, Ni, Cu, Au, Ag, Pt, and Pd are considered. The final structures of united bimetallic clusters are classified into the three categories, epitaxial, core-shell, and alloyed structures. Which type of structure is realized via coalescence depends on the size and temperature of clusters, that can be summarized in phase diagrams., Domestic conference
06 Mar. 2009

Nanomechanical analysis of silicon nanoparticles
T. Nakajima; K. Shintani
Oral presentation, Japanese, The 15th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Mito, Since the melting point and the bulk modulus of nanoparticles (NPs) vary with the change of their size, the mechanical properties of NPs attract much attention. The molecular-dynamics simulations of uniaxial compression of NPs of Si are performed using Erhart potential. A Si NP is pinched by parallel rigid plates of diamond as indenters. The indenters are forced to a target position within the Si NP, and then reversed. As mulitiple compression cycles progress, irreversible deformation of the Si NP is observed., Domestic conference
06 Mar. 2009

Analysis of synthesis of bimetallic clusters
S. Mizuno; K. Shintani
Oral presentation, Japanese, Mechanical Engineering Congress, 2008 Japan (MECJ-08), Japan Society of Mechanical Engineers, Yokohama, Coalescence of two metallic clusters of different species is studied using molecular-dynamics simulation. The morphologies of a united cluster are categorized into the three kinds, core-shell, alloyed, and epitaxially-joined clusters. Which morphology is taken by a united cluster depends on the combination of the surface energies and atomic sizes of the original clusters.
06 Aug. 2008

Analysis of oscillations of double-walled carbon nanotubes on a graphite substrate
Kazuki Sato; Kazuhito Shintani
Poster presentation, Japanese, 2008 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法によって、グラファイト基板上の二層カーボンナノチューブ（DWCNT）の振動シミュレーションを行った。その結果、グラファイト基板上のDWCNTの振動は、自由空間における振動に比べて減衰が激しく対数減衰率は3～15倍程度になること、グラファイト基板上では振動するDWCNTが回転することが分かった。, Domestic conference
06 Jun. 2008

Analysis of the electronic and mechanical properties of carbon nanomaterials
H. Tomisu; K. Shintani
Oral presentation, Japanese, The 14th-Term Plenary Meeting of the Kanto Branch of the Japan Society of the Mechanical Engineers, Japan Society of Mechanical Engineers, Tokyo, Carbon nanomaterials such as graphene and carbon nanotubes (CNTs) attract much attention of researchers because they are applicable to mechanical and electronic nanodevices. In this paper, how the electronic properties of CNTs change when they are deformed is investigated by means of the first principles calculation. As the electronic properties, the band structures and dielectric functions of CNTs are focused on., Domestic conference
15 Mar. 2008

Atomistic analysis of the interface between a gold thin film and a silicon substrate
Taka-aki Nakajima; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会M&M2007材料力学カンファレンスCD-ROM論文集, The morphological transformation and change of composition of gold-silicon alloy at the interface between a Au thin film and a Si substrate are studied using classical molecular-dynamics analysis. The simulation employs the modified embedded-atom method potential extended to the Au-Si system by Kuo and Clancy. After the system is equilibrated at room temperature, it is annealed above eutectic temperature. The most stable composition and structure of Au-Si alloy at the interface is obtained., Domestic conference
26 Oct. 2007

Molecular-dynamics analysis of the formation of an alloyed cluster via coalescence of two metallic clusters of different elements
Shinya Mizuno; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部ブロック合同講演会2007さいたま/第3回埼玉ブロック大会講演論文集, Japan Society of Mechanical Engineers, Saitama, 正二十面体構造を有する異種金属クラスターの合体過程を分子動力学シミュレーションによって追跡した。合体後のクラスターの表面と内部のモルフォロジーが合体前のクラスターの原子種と温度にどのように依存するか調べた。, Domestic conference
22 Sep. 2007

Study of coalescence of clusters of different species
Keita Takami; Kazuhito Shintani
Poster presentation, Japanese, 2007 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 異種原子クラスターの合体の進行過程、合体後のクラスターの表面と内部のモルフォロジーが原子種、初期温度、初期構造にどのように依存するかを分子動力学シミュレーションによって調べた。その結果、Au-Ag、Au-Feのいずれの合体においても、自発的合金化が進むことが分かった。, Domestic conference
25 May 2007

Ar-buffer-assisted deposition of a Cu cluster on a Cu substrate
Shinya Mizuno; Kazuhito Shintani
Poster presentation, Japanese, 2007 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, Ar雰囲気中でCu(100)基板上に正20面体構造のCuクラスターを堆積させて、堆積の過程、堆積後のクラスターの構造を分子動力学シミュレーションによって調べた。その結果、温度300Kで堆積するクラスターは基板と同じ結晶構造に再構成すること、Ar雰囲気によってクラスターの運動エネルギーは散逸しクラスターは基板上にソフトランディングすることが分かった。, Domestic conference
25 May 2007

Molecular-dynamics study of carbon nanotubes with Stone-Wales defects
Yusuke Mimura; Taka-aki Nakajima; Kazuhito Shintani
Poster presentation, Japanese, 2007 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法により、Stone-Wales（SW）欠陥を有する単層カーボンナノチューブ（SWCNT）の引張・圧縮シミュレーションを行い、ヤング率と座屈特性に及ぼすSW欠陥の影響を調べた。その結果、SW欠陥の数の増加に比例してヤング率が減少すること、SW欠陥の存在により座屈開始応力が変化することが分かった。, Domestic conference
25 May 2007

Molecular-dynamics analysis of the mechanical properties of double-walled carbon nanotubes
Yasuyoshi Ohi; Taka-aki Nakajima; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第13期総会講演会講演論文集 No. 070-1, Japan Society of Mechanical Engineers, Utsunomiya, Oscillations of double-walled carbon nanotubes are studied using molecular-dynamics simulation. The oscillatory frequencies of double-walled carbon nanotubes are found to be near 55.6GHz. How the logarithmic decrements of the oscillations depend on the diameters of carbon nanotubes is investigated., Domestic conference
17 Mar. 2007

Molecular-dynamics analysis of coalescence of different metallic clusters
Yusuke Kometani; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第13回総会講演会講演論文集 No. 070-1, Japan Society of Mechanical Engineers, Ustunomiya, Coalescence of Cu and Au clusters is studied by means of molecular-dynamics simulation. The interactions between Cu and Au atoms are calculated using the generic embedded-atom method potential. Before coalescence, Cu and Au clusters are assumed to have fcc and icosahedral structures. Their morphological changes after coalescence are tracked, and the mechanism of formation of a core-shell cluster is especially focused on., Domestic conference
17 Mar. 2007

Molecular-dynamics analysis of the structural and mechanical properties of semicondutor hetero-nanowires
Yuichi Yano; Taka-aki Nakajima; Kazuhito Shintani
Oral presentation, Japanese, NCTAM 2007(The National Congress of Theoretical and Applied Mechanics 2007), Science Council of Japan, Tokyo, The mechanical properties of Ge/Si core-shell nanowires under a uniaxial tension are studied by means of molecular-dynamics simulation. The effects of the axial direction and the fraction of the core atoms upon the Young's moduli of the core-shell nanowires are investigated. The values of the Young's moduli are compared with those calculated using Vegard's law. It is found that single atom chains are formed at the final stages of elongation of the nanowires., Domestic conference
07 Mar. 2007

Molecular-dynamics analysis of deposition of magnetic and nonmagnetic metallic multilayers
Yusuke Kometani; Kazuhito Shintani
Oral presentation, Japanese, The 19th Computational Mechanics Conference, Japan Sciety of Mechanical Engineers, Nagoya, 磁性・非磁性金属の多層膜によって形成される巨大磁気抵抗（GNR）素子の磁気抵抗変化率は非磁性薄膜と磁性膜の界面の状態に依存する。本研究では、分子線エピタキシー（MBE)法によってCo(111)面に堆積するCu膜の成長を分子動力学シミュレーションによって調べた。その結果、Cu原子の入射エネルギーが5eVのときにインターミキシングが少ない良好な界面が得られることが分かった。, Domestic conference
05 Nov. 2006

Molecular-dynamics analysis of the growth of metallic multilayers
Masayuki Ichitsuka; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 2006 Annual Meeting of the JSME/MMD, Japan Society of Mechanical Engineers, Hamamatsu, 巨大磁気抵抗（GMR)多層膜の堆積過程と堆積層の構造を分子動力学シミュレーションによって調べた。磁性体であるNi(001)基板上に非磁性体であるCu原子を堆積させ、その後さらにNi原子を堆積させる分子線エピタキシー（MBE）法に対応したシミュレーションを行った。その結果、すべての条件においてエピタキシャル成長が確認され、Cu、Ni堆積原子の速度が大きいほどNi層とCu層の界面ならびにNi層表面が滑らかになることが分かった。, Domestic conference
04 Aug. 2006

Molecular-dynamics study of deposition of a Co cluster on a Cu substrate
Kazuhiro Terajima; Kazuhito Shintani
Poster presentation, Japanese, 2006 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法により、CoクラスターをCu基板上に堆積させてその後やきなましを施すシミュレーションを行い、基板方位と温度が堆積後のクラスターの構造に与える影響を調べた。その結果、堆積後のクラスターの構造変化は温度に強く依存すること、高温における構造変化は、エピタキシャル構造への変化、表面におけるファセット形成、Co原子のCu基板への固溶の3段階を踏むことが分かった。, Domestic conference
May 2006

Molecular-dynamics analysis of the mechanical properties of carbon nanotubes using the second-generation REBO potential
Shuhei Sato; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第12期総会講演会講演論文集 No. 060-1, Japan Society of Mechanical Engineers, Kawagoe, The mechanical properties of carbon nanotubes are investigated by molecular dynamics simulation. The interactions between carbon atoms are calculated using the second generation reactive empirical bond order (REBO) potential. The Young's moduli of carbon nanotubes with various lengths are computed. It is shown that the Young's moduli of carbon nanotubes depend on their lengths and the elongation speed., Domestic conference
10 Mar. 2006

Molecular-dynamics simulation of the deposition process of SiGe
Yuichi Yano; Masashi Abe; Kazuhito Shintani
Poster presentation, Japanese, 2005 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, Si(001)基板上へのGe原子堆積過程あるいはGe原子とSi原子の堆積過程を分子動力学シミュレーションによって調べた。その結果、基板の過渡的表面には(110)ダイマー列が形成されること、エピタキシャル成長が止まる臨界膜厚はGe原子だけを堆積させる場合の方がGe原子とSi原子を交互に堆積させる場合よりも大きいことが分かった。, Domestic conference
03 Jun. 2005

Molecular-dynamics simulation of the deposition process of Ge atoms
M. Abe; K. Shintani
Oral presentation, Japanese, 日本機械学会関東支部第11期総会講演会講演論文集, Japan Society of Mechanical Engineers, Tokyo, Heteroepitaxial growth of Ge atoms on a Si substrate is investigated by using a classical molecular dynamics method with the Tersoff potential. The simulation begins with preliminary equilibration of the substrate at a specified temperature, and 256 Ge atoms with the energy of 0.2eV are deposited one by one on the substrate. As deposition proceeds, the potential energy of the deposited Ge atoms increases. This tendency makes a remarkable contrast with that of Si atoms deposited on a Si substrate. A few monolayers of Ge atoms in the initial period grow epitaxially, and the subsequent layers form amorphous-like structures. In the epitaxial growth mode, 2×1 dimer rows are observed to align along the alternately perpendicular <110> directions in the successive atomic layers., Domestic conference
19 Mar. 2005

Analysis of the mechanical properties of one-dimensional nanomaterials by means of molecular-dynamics simulation
Shunji Kameoka; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第11期総会講演会講演論文集, Japan Society of Mechanical Engineers, Tokyo, Deformations of gold nanowres of helical multi-shell structures and fcc structures under a tensile external force are investigated by molecular-dynamics simulation. The interactions between gold atoms are calculated using the modified embedded-atom method potential. The Young's moduli of six nanowire models are obtained, and their structural dependence is discussed., Domestic conference
19 Mar. 2005

Nanomechanics by means of molecular-dynamics simulation
新谷一人
Invited oral presentation, Japanese, 平成16年度材料科学基礎講座ナノ材料設計・評価のためのシミュレーション技術, Invited, Materials Science Society of Japan, Tokyo, 分子動力学シミュレーションの基本的な計算手法の解説と第一原理計算の簡単な紹介を行い、ナノ材料解析への応用例を示した。, Domestic conference
19 Nov. 2004

Molecular-dynamics analysis of the mechanical properties of metallic nanowires
Shunji Kameoka; Naoki Oishi; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会2004年度年次大会講演論文集 Vol. 6, Japan Society of Mechanical Engineers, Sapporo, Deformation of gold nanowires of helical multi-shell structures and fcc structures under a tensile external force is investigated by molecular dynamics. The Young's moduli of the nanowires are obtained, and their dependence on the structures is discussed., Domestic conference
07 Sep. 2004

Molecular-dynamics analysis of the morphology of a nanocluster nealy at melting temperature
M. Nakagawa; S. Kameoka; K. Shintani
Oral presentation, Japanese, 日本機械学会2004年度年次大会講演論文集 Vol. 6, Japan Society of Mechanical Engineers, Sapporo, The morphological transition of a gold cluster nearly at the melting temperature is studied. Clusters of specified sizes are cut out from the bulk crystal structure. The morphological transition of a cluster is followed along the melting-solidifying curve. Whether a cluster is in a solid state or in a liquid state at a given temperature is judged by tracking the radial distribution function. In its solid state, nearly icosahedral structures can be identified., Domestic conference
07 Sep. 2004

Molecular-dynamics study of the formation and mechanical properties of amorphous silicon
Kota Yamaya; Kazuhito Shintani
Oral presentation, Japanese, 2004 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法によって、結晶シリコンからアモルファス構造のシリコンを作成し、結晶シリコンとアモルファスシリコンの引張シミュレーションを行った。その結果、温度100K～200Kの範囲では、アモルファスシリコンのヤング率は結晶シリコンのヤング率よりも小さいことが分かった。, Domestic conference
28 May 2004

Molecular-dynamics analysis of the mechanical properties of Au nanowires of helical structures
Shunji Kameoka; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部創立10周年記念第10期総会講演会講演論文集, Japan Society of Mechanical Engineers, Tokyo, Deformation of gold nanowires under enforced elongation is addressed by means of molecular dynamics. It is found linear strands of gold atoms appear during the elongation., Domestic conference
05 Mar. 2004

Molecular-dynamics analysis of the morphology and deposition process of metallic nanoclusters
Kazuhito Shintani; Yutaka Taniguchi
Oral presentation, Japanese, Proceedings of the 2003 Annual Meeting of the JSME/MMD, Japan Society of Mechanical Engineers, Toyama, The initial period of the deposition of a metallic cluster on a substrate in the soft-landing regime is investigated by molecular dynamics simulation. The simulation reveals that in some cases, the potential energy of the system decreases monotonically after a cluster has been deposited while in the other cases, the potential energy has a local minimum. The existence of this local minimum can be understood by considering the increase of the surface energy during the morphological change of a cluster by which it crystallographically accommodates itself to the surface structure of the substrate., Domestic conference
26 Sep. 2003

Molecular-dynamics analysis of deformation behaviors of gold nanowires
Kazuhito Shintani; Shunji Kameoka; Taka-aki Nakajima
Oral presentation, Japanese, 日本機械学会2003年度年次大会講演論文集(VI), Japan Society of Mechanical Engineers, Tokushima, Metallic nanowires have drawn much attention of researchers since a single-atom chain of gold atoms at a nanocontact between a probe tip and a metal surface was observed. They are applicable to wiring in nanocircuits. Understanding their deformation mechanism is essential to realization of such an application. In this molecular-dynamics study, deformation of gold nanowires under an enforced elongation is addressed. Two kinds of model nanowires are prepared. The modified embedded-atom method potential is employed for calculating the interactions between gold atoms. Before elongation, a model nanowire is equilibrated at a specified temperature. The atoms at one end of the nanowire are moved translationaly in the direction along the nanowire axis. It is found single-atom chains or linear strands of gold atoms are created in the elongation process., Domestic conference
06 Aug. 2003

Molecular-dynamics analysis od twisted carbon nanotubes
Masashi Abe; Kazuhito Shintani
Poster presentation, Japanese, 2003 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法によって単層カーボンナノチューブ（SWCNT)のねじり変形シミュレーションを行った。その結果、SWCNTは広い弾性域を有すること、ねじり剛性は温度の上昇とともに減少し、また、カイラル角依存性を示すことが分かった。, Domestic conference
30 May 2003

Molecular-dynamics simulation of deformation of Au nanowires
Shunji Kameoka; Kazuhito Shintani
Poster presentation, Japanese, 2003 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法によって、金ナノワイヤの引張とねじりの変形シミュレーションを行った。その結果、7-1金ナノワイヤの引張過程においては3本の原子鎖が形成されること、ねじりによって7-1金ナノワイヤの外郭構造を変化させることが可能であることが分かった。, Domestic conference
30 May 2003

Study of the deformation behaviors of nanomaterials by the molecular-dynamics simulation
Taka-aki Nakajima; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第9期総会講演会講演論文集, Japan Society of Mechanical Engineers, Yokohama, Nanomaterials such as carbon nanotubes and nanowires have the electronic and mechanical properties peculiar to nanoscale. In this molecular dynamics study, the deformation of gold nanowires under tensile load are addressed. Model nanowires of three kinds of stacking are considered. The modifed embedded-atom method potential is employed to calculate the interaction between gold atoms. Before tensile process, a model nanowire is equilibrated at a specified temperature. The external force in the axial direction is exerted on the atoms at the ends of the nanowire. The effect of crystallographic anisotropy on the deformation behaviors of nanowires is investigated., Domestic conference
15 Mar. 2003

Simulation of the initial period of cluster deposition
Kazuhito Shintani; Taka-aki Nakajima; Yutaka Taniguchi
Oral presentation, Japanese, The 15th Computational Mechanics Conference, Japan Society of Mechanical Engineers, Kagoshima, AuクラスターのAu基板上への堆積過程を分子動力学シミュレーションによって調べた。Auクラスターの速度については、基板にソフトランディングする場合と低エネルギー分子線エピタキシーに対応する場合の2種類を仮定した。堆積したクラスターの構造に及ぼすクラスターサイズと温度の影響を調べた。, Domestic conference
02 Nov. 2002

Modelling of deformation behaviors of nanoscaled materials
Kazuhito Shintani; Taka-aki Nakajima; Kouta Yamaya
Oral presentation, Japanese, Mechanical Engineering Congress, 2002 Japan (MECJ-02), Japan Society of Mechanical Engineers, Tokyo, Since the discovery of a linear strand of gold atoms at a nanocontact between a STM probe tip and a metal surface, nanowires of metals and semiconductors have drawn much attention of researchers in the field of nanotechnologies. Nanowires are expected to show both the electronic and mechanical properties peculiar to nanoscale. In this study, molecular dynamics simulation is employed to study deformations of gold nanowires under tensile strains. The interaction forces between atoms are calculated by using the embedded-atom method potential. Before a tensile process, the model nanowire is equilibrated at a specified temperature. While a few layers at one end of the nanowire are kept fixed, the ones at the opposite end are forced to be displaced. How the anisotropy of the nanowires affects their deformation behaviors and mechanical properties is investigated., Domestic conference
27 Sep. 2002

Molecular dynamics simulation of the elementary process of silicon MBE
中島隆明; 新谷一人
Oral presentation, Japanese, 日本材料科学会第9回材料科学若手研究者討論会講演予稿集, Materials Science Society of Japan, Tokyo, 分子動力学法によって、Si(001)基板上へのSi原子のMBE成長過程のシミュレーションを行った。その結果、Si原子がエピタキシャル成長する場合には、直交するダイマー列が交互に形成されることに結晶成長が進むことが分かった。, Domestic conference
30 Jul. 2002

Molecular-dynamics simulation of the initial period of low-energy Au cluster beam deposition
Taka-aki Nakajima; Masashi Oba; Kazuhito Shintani
Oral presentation, Japanese, 2002 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, クラスタービーム堆積法は、クラスターの運動エネルギーの大きさによって、ソフトランディング、低エネルギークラスタービーム堆積、エネルギークラスター衝撃の3種類のカテゴリーに分類される。本研究では、AuクラスターのAu基板上へのソフトランディングと低エネルギークラスタービーム堆積のシミュレーションを行った。その結果、堆積したクラスターはいずれもエピタキシャル構造をとるが、低エネルギークラスタービーム堆積の場合、クラスターは基板の構造を破壊しながら基板内へ侵入することが分かった。, Domestic conference
31 May 2002

Molecular dynamics simulation of silicon MBE
Taka-aki Nakajima; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第８期総会講演会講演論文集, Japan Society of Mechanical Engineers, Funabashi, The deposition process of Si atoms on a Si(001) surface is simulated by the method of molecular dynamics. The Stillinger-Weber potential is used for calculation of interatomic forces. During the deposition, the lower part of the substrate is held at an initially specified temperature by velocity scaling. The simulations were performed at several temperatures in order to investigate the influence of substrate temperatures on the growth morphology of an overlayer. The conditions that the deposited atoms form a crystal structure or an amorphous one are sought., Domestic conference
16 Mar. 2002

Molecular dynamics study of the mechanical properties of carbon nanotubes
Takayishi Narita; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第８期総会講演会講演論文集, Japan Society of Mechanical Engineers, Funabashi, The mechanical properties of single-walled carbon nanotubes are investigated by means of molecular dynamics simulations. The Brenner potential is used for calculation of interatomic forces. Two kinds of simulation cells are considered; one adopts a periodic boundary condition along the tube axis whereas another includes a tube cluster. The atoms at the ends of a simulation cell are translated along its axis, and the Poisson's ratio and Young's modulus are estimated. How these mechanical properties of carbon nanotubes depend on their chiralities is discussed., Domestic conference
16 Mar. 2002

Molecular dynamics simulation of interaction between dislocations
Taka-aki Nakajima; Kazuhito Shintani
Oral presentation, Japanese, 2001 JSME Annual Meeting, Japan Society of Mechanical Engineers, Fukui, The interaction between dislocations in Cu crystals are investigated by means of molecular dynamics simulations where the EAM potential function is used in order to calculate the interatomic forces. By visualizing the energy levels of atoms, the dislocations introduced in Cu are found to be extended in the process of equilibration of the molecular dynamics method, and the stacking faults are identified., Domestic conference
29 Aug. 2001

Molecular dynamics simulation of surface migration of silicon atoms
Masayoshi Nishimura; Kazuhito Shintani
Oral presentation, Japanese, 2001 JSME Annual Meeting, Japan Society of Mechanical Engineers, Fukui, The behaviors of a Si atom or a Ge atom diffusing on a Si(001) stepped surface are investigated by the method of molecular dynamics in order to understand the elementary processes of the molecular beam epitaxial growth of the deposited atoms. In the calculation of the interatomic forces, the Stillinger-Weber potential is used. The sequential depositions of Si or Ge atoms are also simulated, and the condition that the deposited atoms form a crystal structure or an amorphous one are sought., Domestic conference
29 Aug. 2001

Analysis of surface morphology of thin films on twist-bonded substrates
Yoshiyuki Obayashi; Kazuhito Shintani
Oral presentation, Japanese, 2001 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, ねじれ接合基板上薄膜の表面モルフォロジーに対して、ねじれ境界に存在するらせん転位列の影響を調べた。その結果、ねじれ角がある程度大きく、また、ねじれ境界が表面からある程度離れていれば、層表面のうねりを小さくできることが分かった。, Domestic conference
25 May 2001

Molecular dynamics simulation of semconductor nano-structures
Hirotsugu Sugii; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第7期総会講演会講演論文集, Japan Society of Mechanical Engineers, Tokyo, The molecular beam epitaxial growth of Si/Si and Ge/Si systems are investigated by molecular dynamics simulations. It is found that deposited atoms are likely to move along dimer arrays and that whether deposited atoms form a crystal structure or an amorphous one depends on the temperature of a substrate and the energy of deposited atoms., Domestic conference
16 Mar. 2001

Numerical simulation of dislocation dynamics
Tsuyoshi Miyata; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会関東支部第7期総会講演会講演論文集, Japan Society of Mechanical Engineers, Tokyo, The evolution processes of dislocations are simulated by discretizing dislocation lines into dislocation segments. First, it is found that the dislocation multiplication by the Frank-Read mechanism under an external shear stress is realized. Second, the critical thicknesses of heteroepitaxial films are estimated by considering the nucleation and extension of dislocation half-loops., Domestic conference
16 Mar. 2001

Influence of screw dislocations on strain relaxation in heteroepitaxial films over twist-bonded substrates
Yoshiyuki Obayashi; Kazuhito Shintani
Oral presentation, Japanese, The 13th Computational Mechanics Conference, Japan Society of Mechanical Engineers, Toyohashi, ねじれ結合基板上のヘテロエピタキシャル層の表面拡散による表面形状の発展方程式を用いて安定性解析を行い、ねじれ境界のらせん転位列による応力場が表面モルフォロジーの変化に及ぼす影響を調べた。, Domestic conference
29 Nov. 2000

Analysis of semiconductor nano-structures by the method of molecular dynamics
Hirotsugu Sugii; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 2000 Annual Meeting of JSME/MMD, Japan Society of Mechanical Engineers, Yokohama, 分子動力学法を用いて、分子線エピタキシー（MBE)によるSi/SiあるいはGe/Si薄膜の結晶成長過程のシミュレーションを行い、薄膜構造の温度依存性を調べた。, Domestic conference
07 Oct. 2000

Analysis of strain relaxation mechanisms in heteroepitaxial layers on twist-bonded compliant substrates
Yoshiyuki Obayashi; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 2000 Annual Meeting of JSME/MMD, Japan Society of Mechanical Engineers, Yokohama, ねじれ結合薄膜基板に対してKastner et al.が提案した転位の分離とすべりによるひずみ緩和機構について、この機構が働く条件を調べた。その結果、この機構は、ねじれ角が低角度でねじれ結合薄膜基板の厚さが小さい場合に、らせん転位から解離した部分転位列によって起こり得ることが分かった。, Domestic conference
07 Oct. 2000

Effect of surface steps on the strain relaxation mechanism of thin solid films: Molecular dynamics simulation
Atsushi Honda; Kazuhito Shintani
Oral presentation, Japanese, 2000 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 分子動力学法によって、Si薄膜のひずみ緩和に及ぼす表面ステップの影響を調べた。その結果、Si薄膜の結晶構造変化は表面ステップを起点として起こること、表面で発生した結晶構造の変化が薄膜内部に伝播し広がっていくことによりひずみが緩和されエネルギーが低下することが分かった。, Domestic conference
26 May 2000

Critical thickness of a heteroepitaxial film on a twist-bonded compliant substrate
Yoshiyuki Obayashi; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会東海支部第49期総会講演会講演論文集, Japan Society of Mechanical Engineers, Nagoya, Jesser et al.が提案した機構に基づいて、ねじれ結合コンプライアント基板上のヘテロエピタキシャル層におけるミスフィット転位形成に対する臨界膜厚を求めた。Ejeckam et al.の実験結果は、Jesser et al. の提案した機構によって説明できることが分かった。, Domestic conference
11 Mar. 2000

Atomistic simulation of strain distributions in quantum dots
Motohiro Kobayashi; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会東海支部第49期総会講演会講演論文集, Japan Society of Mechanical Engineers, Nagoya, 共役勾配法によるエネルギー最小化により、ピラミッド型InAs/GaAs量子ドットのひずみ分布を求めた。原子間相互作用の計算にはStillinger-Weberポテンシャルを用いた。その結果、基板を剛体と仮定してもひずみ分布の計算に大きな影響はないが、wetting layerの厚さはひずみ分布に影響することが分かった。, Domestic conference
11 Mar. 2000

Molecular dynamics study of strain effects on Raman frequencies of Ge/Si systems
Hirotsugu Sugii; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会東海支部第49期総会講演会講演論文集, Japan Society of Mechanical Engineers, Nagoya, ラマン分光法ではラマン振動数の変化（ラマンシフト）に対して換算係数を適用することによってひずみを測定する。本研究では、Ge/Si層のラマン振動数を分子動力学法によって計算し、換算係数の決定を試みた。, Domestic conference
10 Mar. 2000

Numerical analysis of strain distributions for quantum dots using empirical potentials
Yukinori Kikuchi; Kazuhito Shintani
Oral presentation, Japanese, 1999 JSME Annual Meeting, Japan Society of Mechanical Engineers, Tokyo, The stable atomic structures of the capped or noncapped Ge quantum dots on the Si substrate are obtained by the conjugate gradient minimization of the potential energy of the system. The Stillinger-Weber, Tersoff, and Valence Force Field (VFF) potentials are adopted. The Ge quantum dots are assumed to be of pyramidal shapes with {110} or {105} facets. The strain distributions along the three selected paths are calculated. It is shown the strain distributions obtained by using the Stillinger-Weber and VFF potentials are in good agreement with each other., Domestic conference
27 Jul. 1999

Atomistic simulation of quantum dots by the conjugate gradient method
Hirotsugu Sugii; Yukinori Kikuchi; Kazuhito Shintani
Oral presentation, Japanese, 日本材料科学会平成11年度学術講演大会講演予稿集, Materials Science Society of Japan, Tokyo, 共役勾配法によるエネルギー最小化により{105}あるいは{110}ファセットを有するSi/Ge/Si量子ドットのひずみ分布を求めた。原子間相互作用の計算には、Stillinger-Weber、Tersoff、VFFポテンシャルを用いた。その結果、Stillinger-WeberポテンシャルとVFFポテンシャルによるひずみ分布は近い値を示すが、小さなサイズの量子ドットに対してはStillinger-Weberポテンシャルを使用する必要があることが分かった。, Domestic conference
28 May 1999

Analysis of strain relaxation mechanisms in heteroepitaxial layers
Yoshiyuki Obayashi; Kazuhito Shintani
Oral presentation, Japanese, The 76th JSME Fall Annual Meeting, Japan Society of Mechanical Engineers, Sendai, Many experimental results suggest that misfit dislocation formation and surface undulation are main mechanisms for strain relaxation in plane-strained coherent lattice-mismatched layers. In order to investigate which mechanism dominantly operates, we compare the relationship between critical wave lengths for stability of surface sinusoidal undulations and layer thickness with the critical thickness for misfit dislocation formation, which are approximately calculated in the anisotropic layer on a rigid substrate. Critical wave lengths are obtained by considering the free energy change of the system, and critical thicknesses are determined by using the image force theorem. Numerical results for SI_{1-x}Ge_{x}/Si systems show that misfit dislocation generation is likely to occur for x<0.5, whereas surface undulation is likely to occur for x>0.5. This tendency is in agreement with the feature which has been experimentally observed in the literature., Domestic conference
03 Oct. 1998

Molecular dynamics simulation of semicondutor surfaces
Yukinori Kikuchi; Kazuhito Shintani
Oral presentation, Japanese, The 76th JSME Fall Annual Meeting, Japan Society of Mechanical Engineers, Sendai, Molecular dynamics simulation using the Stillinger-Weber potential is performed for surface imperfections on the Ge/Si and Si/Ge heteroepitaxial layers. Three kinds of surface imperfections are considered; double ledge, S_{A} step, and S_{B} step. Computational cells consist of 460 to 500 atoms. It is found that atomistic structures do not almost change under tensile strains while surface reconstruction occurs under compressive strains. However, we find that all structures reach readily-steady states. As a result, no nucleation of dislocations occurs, which is contrary to the results of Zimmerman and Gao (1996)., Domestic conference
03 Oct. 1998

Anisotropic analysis of surface morphology in heteroepitaxial layers
Yoshiyuki Obayashi; Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会東海支部第47期総会講演会講演論文集, Japan Society of Mechanical Engineers, Nagoya, ヘテロエピタキシャル層表面のうねりに対する安定性解析を行った。Freund &Jonsdottir (1993)の定式化に従い、異方性を考慮した系の自由エネルギーの時間に関する2階導関数のt=0における値を求めて安定性を議論した。, Domestic conference
06 Mar. 1998

Analysis of blocking effect of misfit dislocations
Yoshitaka Sase; Kazuhito Shintani
Oral presentation, Japanese, The 74th JSME Fall Annual Meeting, Japan Society of Mechanical Engineers, Kyoto, At the extension of misfit dislocations in epitaxial layer structures, threading dislocations which precede misfit dislocations are frequently influenced by the other misfit dislocations lying in the cross glide planes. By using Freund's general definition for the driving force exerted on a threading dislocation, the blocking forces by one or two misfit dislocations are calculated taking the image stresses into account. The numerical result shows that the surface effect cannot be neglected for the estimation of such interaction forces. The channel widths through which threading dislocations can glide in the layer are also calculated for the two blocking misfit dislocations., Domestic conference
21 Sep. 1996

Analysis of critical thicknesses of epitaxial films taking image forces into account
Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 8th Computational Mechanics Conference, Japan Society of Mechanical Engineers, Nagano, 基板とその上に成長されるヘテロ薄膜との間の界面には、ヘテロ薄膜の厚さが臨界値を超えるとミスフィット転位が形成される。この臨界膜厚の値を、貫通転位‐ミスフィット転位（アンギュラー転位）間の相互作用と鏡像力を考慮して計算した。その結果、臨界膜厚は、アンギュラー転位の相互作用により、Matthews-Blakeslee臨界膜厚の10～25％減少することが分かった。, Domestic conference
17 Nov. 1995

On the interaction characteristics of dislocation loops in epitaxial layers
Kazuhito Shintani; Yuji Yao
Oral presentation, Japanese, Proceedings of the 1995 Annual Meeting of JSME/MMD, Japan Society of Mechanical Engineers, Morioka, To examine the properties of SiGe/Si epitaxial structures, two model calculations are executed. Firstly, we calculate the interaction energy between two surface half loops either lying in parallel slip planes or lying each in a primary slip plane and in the cross slip plane. Secondly, we calculate the forces exerted on threading dislocation segments interacting with each other in the same slip plane., Domestic conference
23 Aug. 1995

Analysis of the critical thickness of epitaxial layers by using the dislocation-loop nucleation model
Kohsaku Fujita; Kazuhito Shintani
Oral presentation, Japanese, 1995 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, 鏡像力定理と折れ曲がった転位の応力場を基に、表面から形成されてすべり面上に存在する転位ループの自己エネルギーを計算した。このエネルギーと緩和されるミスフィットひずみエネルギーとの比較により、エピタキシャル膜の臨界膜厚を計算した。その結果、転位を全空間あるいは半空間内の半円ループとして計算した臨界膜厚よりも、鏡像の影響を正しく考慮した今回の臨界膜厚のほうが大きくなることが分かった。, Domestic conference
26 May 1995

Effects of dislocation-loop interaction and anisotropy on critical thicknesses of epitaxial films
Hisanori Yonezawa; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 72nd JSME Spring Annual Meeting, Japan Society of Mechanical Engineers, Tokyo, Based on van de Leur et al.'s model which deals with the energy of a dislocation half-loop, the critical thickness of Si_{1-x}Ge_{x} epitaxial films are determined under isotropic assumption. Blin's formula yields the interaction energy of two dislocation loops lying in coplaner or parallel slip planes. The anisotropic critical thicknessis obtained using Willis's energy formula. The result is compared with the isotropic critical thickness., Domestic conference
30 Mar. 1995

Energy of misfit dislocation arrays and their stability
Koichi Asaka; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 72nd JSME Spring Annual Meeting, Japan Society of Mechanical Engineers, Tokyo, The anisotropic closed-form solution for the energy of dislocation arrays lying in the interface between a strained epitaxial film and a substrate is obtained. The effect of the free surface is considered by using the image force theorem by Barnett and Lothe. The dislocations in one array have the same Burgers vector, and the dislocations in another array have the Burgers vector of the opposite direction, The critical thickness is determined by calculating the total energy with the change of the dislocation density., Domestic conference
30 Mar. 1995

On the stability of misfit dislocations in the interface of thin layers
Kosaku Fujita; Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 72nd JSME Fall Annual Meeting, Japan Society of Mechanical Engineers, Sapporo, By using the anisotropic image force theorem of Barnett and Lothe, single- and double-kink models for capped (buried) Si_{1-x}Ge_{x} strained layers are extended so as to take into account cubic anisotropy with surface effect. The results show that the effect of cubic anisotropy is significant and tends to decrease the excess stress and to increase the critical layer thickness in both of the single- and double-kink models. In addition, the force exerted on a threading dislocation from a misfit dislocation in an isotropic medium is examined in details by using Li's expression., Domestic conference
19 Aug. 1994

Effet of anisotropy on the stability of misfit dislocations in a Si/Si_{1-x}/Ge_{x}/Si structure
Kohsaku Fujita; Kazuhito Shintani
Oral presentation, Japanese, 1994 Annual Meeting of the Materials Science Society of Japan, Materials Science Society of Japan, Tokyo, Si/Si_{1-x}/Ge_{x}/Si構造のSi_{1-x}/Ge_{x}ひずみ層中の単独の転位を扱うシングルキンクモデルと転位の双極子を扱うダブルキンクモデルの2つのモデルに対して、鏡像力と異方性を考慮して臨界膜厚を求めた。その結果、異方性を考慮すると等方性の仮定に基づく臨界膜厚よりもダブルキンクモデルで30％、シングルキンクモデルで20％、それぞれ増加することが分かった。, Domestic conference
31 May 1994

On surface acoustic waves in piezoelectric semiconductors
Kazuhito Shintani; Hideki Itoh
Oral presentation, Japanese, Proceedings of the 1993 Annual Meeting of JSME/MMD, Japan Society of Mechanical Engineers, Sakai, 六方晶系圧電性結晶の基底面上を伝播する弾性表面波（SAW)について、半導体のドリフト電流を考慮した解析を行った。拡散電流を無視し、非漏洩モードのSAWだけを対象とした。GaAs、ZnO、CdSに対して数値計算を行い、ドリフト電流によって誘電緩和周波数の近傍においてSAWの分散が生じることが分かった。, Domestic conference
16 Nov. 1993

Analysis of equilibrium shapes of dislocations in piezoelectric materials under an external stress
Kazuhito Shintani; Sitiro Minagawa
Oral presentation, Japanese, Proceedings of the 1992 Annual Meeting of JSME/MMD, Japan Society of Mechanical Engineers, Sapporo, 圧電性材料内の転位の単位長さあたりの弾性エネルギーと電気的エネルギーに対する一般的表式を用いて、外力下に置かれた三方晶系、六方晶系の圧電性結晶内部の転位ループの平衡形状を計算し、平衡形状に及ぼす圧電効果を調べた。その結果、転位ループの刃状部分において圧電効果が強く表れることが分かった。, Domestic conference
02 Sep. 1993

On the force on the dislocation bends in piezoelectric materials
Kazuhito Shintani
Oral presentation, Japanese, Proceedings of the 70th JSME Spring Annual Meeting, Japan Society of Mechanical Engineers, Hachioji, It is shown that Lothe's theorem regarding the force on dislocation bends is also valid for piezoelectric materials. Brown's proof procedure is followed. The forces on dislocation bends in lithium niobate, which is used as a material for SAW devices, are numerically calculated., Domestic conference
01 Apr. 1993

Dislocation dynamics in a piezoelectric material (Analysis of electric fields around a dislocation loop)
Kazuhito Shintani; Sitiro Minagawa
Oral presentation, Japanese, 日本機械学会機械力学シンポジウム「電磁力関連のダイナミックス」, Japan Society of Mechanical Engineers, Kitashioharamura Hinokihara, ピエゾ効果を有する異方性結晶中の楕円形状の転位ループによって誘導される電場に対する表示式を、連続分布転位論に基づく基礎式から求めた。楕円形状の転位ループ近傍の電場の特性を調べた。, Domestic conference
26 Jun. 1989

Eigenvalue analysis of a one-dimensional dynamically-coupled problem of thermal conduction in a hybrid material
Takeshi Atarashi; Kazuhito Shintani; Sitiro Minagawa
Oral presentation, Japanese, 日本機械学会第949回講演会材料力学講演概要集, Japan Society of Mechanical Engineers, Yokohama, 一様な温度分布を有する積層平板の表面が急激な加熱あるいは冷却を受けるとき、平板には熱流が生じ、それに伴ってひずみと応力が発生する。本研究では、このような複合積層平板の熱伝導問題を取り扱い、温度とひずみの場の連成を考慮して固有値問題として解析した。, Domestic conference
20 Nov. 1987

Electric field induced by a circular dislocation in a piezoelectric crystal
Hiroyuki Kumakura; Kazuhito Shintani; Sitiro Minagawa
Oral presentation, Japanese, 日本機械学会第949回講演会材料力学講演概要集, Japan Society of Mechanical Engineers, yokohama, ピエゾ効果を有する異方性結晶中を等速運動する円形転位が誘導する電場に対する表示式を、連続分布転位論に基づく基礎式から求めた。, Domestic conference
19 Nov. 1987

Elastic and plastic analysis of stress waves created by a thermal shock in a plate
Tishiyuki Shibaki; Kazuhito Shintani; Sitiro Minagawa
Oral presentation, Japanese, 日本機械学会第949回講演会材料力学講演概要集, Japan Society of Mechanical Engineers, Yokohama, エントロピーに対するひずみの影響を無視して、熱衝撃によって一定厚さの平板に生じる応力波の伝播の解析を行った。竹内・古川の表示式を全ひずみ理論によって塑性域まで拡張し、差分法を用いて数値解を求めた。, Domestic conference
19 Nov. 1987

Low-Reynolds number flow around a flat plate
Kazuhito Shintani
Oral presentation, Japanese, 第３２回応用力学連合講演会講演論文抄録集, Japan Society of Mechanical Engineers, Tokyo, 楕円柱まわりの低レイノルズ数流れに対する漸近展開による解に対して離心率が1の極限を考えれば、平板まわりの解を得る。この解を用いて、平板近傍の流れ場を調べて、平板後方の渦形成の様子を明らかにした。, Domestic conference
03 Dec. 1982

Low-Speed Flow around an Elliptic Cylinder(2nd Report, Inertial Effect)
Kazuhito Shintani
Oral presentation, Japanese, 日本機械学会第59期通常総会講演会講演論文集, Japan Society of Mechanical Engineers, Narashino, 楕円柱まわりの低レイノルズ数流れに対する漸近展開による解析を行い、柱近傍の流れの慣性効果を表すレイノルズ数について一次のオーダの解を求めた。, Domestic conference
30 Mar. 1982

Low-Reynolds number flow around an elliptic cylinder
Kazuhito Shintani; Akira Takano
Oral presentation, Japanese, 第13回流体力学講演会講演集, 日本航空宇宙学会・流体力学懇談会, Nagoya, 楕円柱まわりの低レイノルズ数流れに対して漸近展開による解析を行い、柱近傍の流れ場のレイノルズ数について一次のオーダの解を求めた。, Domestic conference
20 Oct. 1981

Low-speed flow around an elliptic cylinder
Kazuhito Shintani; Akira Umemura; Akira Takano
Oral presentation, Japanese, 日本機械学会九州支部講演論文集, Japan Society of Mechanical Engineers, Fukuoka, 楕円柱まわりの低レイノルズ数流れに対する漸近展開による解析を行い、柱近傍の流れを調べた。柱近傍の流れは、楕円の2焦点に配置された特異点によって特徴づけられる。特に、楕円の長軸に垂直に流れがあたる場合、離心率が1/√2を超えるとよどみ点とは異なる点において圧力の最大値が現れることが興味深い。, Domestic conference
18 Mar. 1981

Fundamental analysis of combustion of dispersed particles
Nobunori Oshima; Kazuhito Shintani
Oral presentation, Japanese, 第17回燃焼シンポジウム前刷集, 日本学術会議熱エネルギー工学研究連絡委員会, Nagoya, 噴霧燃焼における液滴群の燃焼過程に対して、１個の液滴の燃焼を代表的に取り扱うセルモデルの方法を適用して、燃焼速度を求めた。, Domestic conference
03 Dec. 1979

Flow through parallel circular cylinders
Kazuhito Shintani; Toyofumi Kato; Satoru Ogawa; Akira Umemura; Nobunori Oshima
Oral presentation, Japanese, 第29回応用力学連合講演会, 日本学術会議力学研究連絡委員会, Tokyo, Domestic conference
21 Nov. 1979

Diffusion of an oil droplet on a water surface
Toyofumi Kato; Kazuhito Shintani; Tsutomu Matsuura; Nobunori Oshima
Oral presentation, Japanese, 第29回応用力学連合講演会, 日本学術会議力学研究連絡委員会, Tokyo, Domestic conference
21 Nov. 1979

Flow through parallel circular cylinders
Toyofumi Kato; Kazuhito Shintani; Satoru Ogawa; Nobunori Oshima
Oral presentation, Japanese, 第28回応用力学連合講演会, 日本学術会議力学研究連絡委員会, Tokyo, Domestic conference
15 Nov. 1978

Dynamics of granular materials including water
Satoru Ogawa; Kazuhito Shintani; Toyofumi Kato
Oral presentation, Japanese, 第28回応用力学連合講演会, 日本学術会議力学研究連絡委員会, Tokyo, Domestic conference
14 Nov. 1978

Drag exerted on cylinders in a low-speed flow
Kazuhito Shintani; Toyofumi Kato; Akira Takano
Oral presentation, Japanese, 第10回流体力学講演会講演集, 日本航空宇宙学会・流体力学懇談会, Kyoto, 円柱群を過ぎる流れを１本の円柱まわりの流れに帰着させて解析するセルモデルの方法によって取り扱い、円柱群の受ける抵抗力を計算して抵抗係数を求めた。その結果を、閉鎖流路内に円柱群を配置し、グリセリン液を流すことによって計測した抵抗係数と比較して、その妥当性を示した。, Domestic conference
21 Oct. 1978

計算力学特論
The University of Electro-Communications

計算力学特論
電気通信大学

材料力学および演習
The University of Electro-Communications

材料力学および演習
電気通信大学

解析学
The University of Electro-Communications

解析学
電気通信大学

基礎解析学
The University of Electro-Communications

基礎解析学
電気通信大学

Japan Society of Mechanical Engineers

Materials Science Society of Japan

Materials Research Society

Atomistic elucidation and control of the mechanical and thermal properties of nanocarbon hybrid structures
2015 - 2017

Atomistic elucidation and control of the mechanical properties of graphene nanostructures
2012 - 2014

Nanoscopic elucidation of coarsening and formation of core-shell nanoparticles via coalescence
2009 - 2011

Elucidation of the growth mechanism and mechanical properties of semiconductor nanowires by means of atomistic simulation
2007 - 2008

Study of the formation process and mechanical properties of surface nanostructures by means of atomistic simulation
SHINTANI Kazuhito
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), 1. Simulations of coalescence of a Au cluster and a Cu cluster were performed. Clusters of fcc and icosahedral structures were created. How the structure, temperature, and size of the clusters before coalescence affect the structure of the coalesced cluster was investigated. It was concluded that an isolated cluster of fcc or icosahedral structure preserves its original shape and remains in the quasi-stable state, that the process of coalescence of clusters consists of spread of Au atoms over the Cu cluster, transfer of the surface energy to the kinetic energy, and progress of alloying at the internal Au/Cu interface, and that an alloyed cluster is created if a Cu cluster and a Au cluster are of about the same size while a core-shell cluster is created if the size of a Au cluster is smaller than that of a Cu cluster. Next, deposition of an icosahedral Cu cluster on a Cu substrate in Ar gas was simulated. The effect of Ar gas on the deposition and on the structural properties of the deposited cluster was investigated. It was concluded that clusters deposited at room temperature become epitaxial, and that since the kinetic energy of a cluster is dissipated by Ar gas, the cluster arrives at a substrate surface without damage and undergoes a nondispersive structural transformation. 2. Simulations of formation of a Co/Cu/Co multilayer were performed. A Co(0001) substrate was created, and 6ML of Cu atoms and 6ML of Co atoms with the velocities corresponding to ones in experiments were deposited on it. The quality of a created multilayer was evaluated by calculating its surface roughness and intermixing. It was concluded that Cuatoms form two-dimensional islands on a Co(0001) substrate, that the higher the incident energy of deposited atoms, the flatter the surface of the deposited atoms, that the best interface is obtained by the deposition of atoms with the energy 5eV among the energies leV, 5eV, and 10eV, and that the usage of the smaller incident energy of Co atoms deposited on a Cu film diminishes the interface roughness and intermixing., 17560066
2005 - 2006

Study of the formation process and mechanical properties of nanoscale materials by means of atomistic simulation
SHINTANI Kazuhito
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), (1) Deposition of Si atoms on a Si substrate was investigated by means of molecular-dynamics simulation. It was concluded that at low temperatures, the initial three or four monolayers of deposited adatoms grow epitaxially while the subsequent layers form an amorphouslike structure, which is consistent with the limited-thickness epitaxy identified in experiments, that the mechanism of epitaxy at nanoscale can be understood by considering repetition of the breaking and renewal of dimer rows on transient growing surfaces, and that the dimer bonds become gradually stabilized as deposition proceeds, and breakdown of epitaxy occurs if the breaking and renewal of dimer rows are interrupted. (2) The molecular-dynamics analysis of morphological evolution of a Au cluster softly-deposited onto a Au substrate was performed. It was concluded that both the clusters in a crystalline state and in a liquid state succeed in epitaxially accommodating themselves to the substrate, that in the accommodation of a crystalline cluster to the substrate at low temperatures, an energy barrier exists, and the cluster becomes finally a facetted epitaxial island, that in the accommodation of a liquid cluster to the substrate at low temperatures, no energy barriers exist, and the cluster becomes an epitaxial island smoothly, and that the morphology of such deposited nanostructures can be controlled by changing the state of free clusters and the substrate temperature. (3) Elongation of Au nanowires was simulated by the molecular-dynamics method. It was concluded that the Young's modulus of a Au nanowire with a helical multi-shell structure is smaller than the Young's modulus of a Au nanowire of the fcc structure with a <110> center axis and with {111} surfaces, that with the increase of temperature, the former decreases more rapidly than the latter, and that a Au nanowire with a helical multi-shell structure can be elongated to produce a single-atom chain of Au atoms., 14550069
2002 - 2003

Study of the strain relaxation mechanism of semiconductor hyperfine structures by means of atomistic simulation
2000 - 2001

Theoretical analysis of the mechanism of strain relaxation of heteroepitaxial layers
SHINTANI Kazuhito
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), 1 The anisotropic linear stability analysis of surface undulations of semiconductor heteroepitaxial layers was performed. Numerical results for SiィイD21-xィエD2GeィイD2xィエD2/Si systems show that the free energy change for the <100> surface undulations is greater than for the <110> undulations, which means surface undulations are likely to be formed in the <100> directions, that the present theory predicts the critical wavelength for the SiィイD20.82ィエD2GeィイD20.18ィエD2/Si system at 444nm which is in good agreement with the experimental value 44Onm, and that the main mechanism of the strain relaxation is the formation of surface undulations at the Ge fraction greater than 0.5 while it is the misfit dislocation generation at the Ge fraction less than 0.5. 2 The molecular dynamics simulations were performed for the dislocation generation from the surface of Si thin films. The Stillinger-Weber potential was used. The effects of surface steps and temperature on the change of the atomic structures are investigated. The simulation results show that at the temperatures 500K and 1000K, the energy decrease always occurs if the strain of the system exceeds a critical value whether there exists a surface step or not and whether the strain is compressive or tensile, that the energy decrease occurs due to the formation of (111) stacking faults either at an arbitrary point on the surface if there is no step or at the surface step if there is one, and that both the SィイD2AィエD2 and SィイD2BィエD2 steps can become generation points of stacking faults and the critical strain for the former is smaller from 1% to 2% than for the latter. 3 The atomistic calculations of the strain profiles within GaAs/InAs/GaAs pyramidal quantum dot structures were performed. The most stable atomic structures were obtained by the conjugate gradient minimization of the system energy expressed in terms of the Stillinger-Weber potential. The results show that there arises tensile strain just above the top of the island, which causes the vertical self-ordering of the stacked dots, that the larger the thickness of the wetting layer, the greater the magnitude of the tensile strain, and that the present results are in good agreement with those obtained by the inclusion theory., 10650074
1998 - 1999

Numerical analysis of the interaction effects of dislocations in epitaxial layers
1996 - 1996

Micromechanics of dislocations in epitaxial films
1995 - 1995

Analysis of the electric fields induced by dislocation loops in piezoelectric crystals
1989 - 1989