KOHJI ABE
| President and Members of the Board of Directors | Special Adviser to the President |
| Emeritus Professor etc. | Emeritus Professor |
Researcher Information
Research Keyword
Career
Educational Background
Member History
- Apr. 2015 - Mar. 2017
日本物理学会代議員, 日本物理学会, Society - Apr. 2015 - Mar. 2016
日本物理学会領域10代表, 日本物理学会 - Apr. 2014 - Mar. 2015
日本物理学会領域10領域副代表, 日本物理学会, Society - 2002 - 2003
editor of the jounal of the physical society of Japan, Society - 2002 - 2003
日本物理学会ジャーナル編集委員, 日本物理学会, Society - 1999 - 1999
フォノン物性分科世話人, 日本物理学会, Society - 1998 - 1998
誘電体文科世話人, 日本物理学会, Society
Research Activity Information
Paper
- Raman spectroscopic studies on the ferroelectric soft mode in Sn_x_Sr_1-x_TiO_3
Tsuguhito Nakano; Yu Mikami; Minoru Kobayashi; Yukihiro Kogai; Kohji Abe
Ferroelectrics, Tayor & Francis, 532, 111-120, 11 Feb. 2019, Peer-reviwed
Scientific journal, English - Managing the learning quality in physics by e-learning improvement with collaborative education
M. Kanenaga; M. Suzuki; K. Abe; J. Nakamura; T. Takada, N; Kokubo; Y. Fuseya
Proceedings of the 12th Asia Pacific Physics Conference, Physical society of Japan, 1, 017018-1-017018-4, Sep. 2014, Peer-reviwed
International conference proceedings, English - Raman Spectroscopic Study of Ferroelectric Sn-Doped SrTiO3
Tsuguhito Nakano; Yu Mikami; Kohji Abe; Shoichiro Suzuki; Kenji Akiyama; Akira Ando
FERROELECTRICS, TAYLOR & FRANCIS LTD, 464, 1, 72-79, May 2014, Peer-reviwed, We measured the Raman spectra of ferroelectric Sn-doped SrTiO3, (Sr1-aSna)(Ti1-bSnb)O-3 (x = a + b = 0.1, 0.05 and 0.02) in the temperature range from 300 to 20K. At room temperature, polar transverse optic modes were observed; which are forbidden in O-h cubic symmetry. The soft mode showed no freezing but remained at constant frequency; it split into two peaks at low temperature. Several modes became active through zone folding below 150K. Instead of freezing of the soft mode, a relaxation mode related to ferroelectricity was found in the low frequency region.
Scientific journal, English - Alignment of Needle TiO2 Nanoparticles in Water
Atsushi Hasagawa; Masamitsu Yoshiki; Tsuguhito Nakano; Kohji Abe; Susumu Sato; Tetsu Yonezawa
International Journal of Theoretiacl and Applied Nanotechnology, Avestia, 2, 1, 18-23, 01 Apr. 2014, Peer-reviwed
Scientific journal, English - Vibrational modes of hydrogens in the proton ordered phase XI of ice: Raman spectra above 400 cm(-1)
Takeshi Shigenari; Kohji Abe
JOURNAL OF CHEMICAL PHYSICS, AMER INST PHYSICS, 136, 17, 174504, May 2012, Peer-reviwed, Polarized Raman spectra of the proton ordered phase of ice Ih, i.e., ice XI, were measured above 400 cm(-1) in the range of librational, bending, and stretching vibrations. Vibrational modes in ice XI, of which symmetry is C-2 nu(12) (Cmc2(1)), were discussed from the group theoretical point of view. In the librational mode spectra below 1200 cm(-1), several new peaks and clear polarization dependencies were observed. Assignments of the librational modes agree reasonably well with the recent MD calculations by Iwano et al. (J. Phys. Soc. Jpn. 79, 063601 (2010)). In contrast, the spectra for bands above 1200 cm(-1) show no distinct polarization dependencies and the spectra resemble those in ice Ih. In ice XI, however, fine structure composed of several weak peaks appear on the broad bending and the combination band. No direct evidence of the LO-TO splitting of the nu(3) anti-symmetric stretching mode was obtained. It is contrary to the case of the translational modes Abe and Shigenari (J. Chem. Phys. 134, 104506 (2011)). Present results suggest that the influence of the proton ordering in ice XI is weaker than the effect of inter-and intra-molecular couplings in the stretching vibrations of ice Ih. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3702595]
Scientific journal, English - Comments on the Unsettled Problems Related to the Origin of the Incommensurate Phase of Quartz
T. Shigenari; K. Abe; M. Yajima; M. Nagamine; D. Semagin; T. A. Aslanyan; S. V. Dmitriev
FERROELECTRICS, TAYLOR & FRANCIS LTD, 433, 1-11, 2012, Peer-reviwed, It is shown that there are several experimental and theoretical results which are not compatible with the currently accepted model for the incommensurate (INC) phase of quartz. In this paper, we comment on the unsettled problems obtained from the light scattering spectra and computational simulations related to the new model for the INC phase.
Scientific journal, English - Light Scattering by Microscopic Granular Ferroelectric Regions in (SrTiO3)-O-18 and Quantum Paraelectrics
T. Nakano; N. Ushio; S. Yamamoto; Y. Sakai; K. Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 441, 1, 67-74, 2012, The transmissions of ferroelectric (SrTiO3)-O-18 (STO18) and quantum paraelectrics SrTiO3, KTaO3 for polarized and depolarized light have been measured. Only for STO18, the transmittance abruptly drops from a few degrees above the ferroelectric transition temperature T-c similar or equal to 25K. The temperature dependence of transmission under crossed Nicols in the vicinity of the phase transition shows that the optical anisotropy appears at 30 K and changes its direction from //[100](c) to //[110](c) or //[1-10](c) across T-c. For sufficiently low temperature below T-c, the orientation of the spontaneous polarization is definitely parallel to [110](c) or [1-10](c).
Scientific journal, English - Observation of Domain Structures Near the alpha-INC-beta Phase Boundary in Quartz Using X-ray Topography
T. Nakano; D. Terada; Y. Kashiwa; M. Toyonaga; J. Nakamura; K. Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 441, 1, 3-8, 2012, The domain structures near the alpha-INC-beta phase boundary in quartz were simultaneously observed using synchrotron radiation X-ray topography and optical microscopy. In (1-10) topographic images of Z-cut samples, a fine structure corresponding to the "m-zone" in the optical microscopic image was observed. In (3-31) topographic image, at the "fog-zone" of the alpha phase side, a marble-like domain, which has never been seen before, with clear contrast was observed. A section topography of the marble-like domain showed that this domain formed a needle shape along the Z-axis. Therefore, the boundary of these domains is the origin of the property of opalescence.
Scientific journal, English - Direction of polarization (P)over-right-arrow and the dipole interaction in the ferroelectric phase of (SrTiO3)-O-18
T. Shigenari; T. Nakano; K. Abe
EPL, EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY, 94, 5, 57001-1-57001-5, Jun. 2011, Peer-reviwed, The structure of isotope-substituted (SrTiO3)-O-18 (STO18) below T-c = 24K has not been made fully understood yet. We have shown that it is orthorhombic C-2v with polarization (P) over right arrow parallel to [110](c), but other groups reported other structures such as (P) over right arrow parallel to[111](c) and (P) over right arrow parallel to[100](c). In this paper, it is shown that the dipole interaction between the rhombohedral polar clusters which has been revealed by NMR (BLINC R. et al., Phys. Rev. Lett., 94 (2005) 147601) is the very probable reason for the formation of (P) over right arrow parallel to[110](c). The dipole interaction model is consistent with various peculiarities observed in the Raman spectra (SHIGENARI T. et al., Phys. Rev. B, 74 (2006) 174121) such as the inhomogeneity, the imperfect softening and the appearance of the relaxational mode near T-c. Copyright (C) EPLA, 2011
Scientific journal, English - Vibrational Spectra of Ice Ih and XI Phases in KOH Doped Single Crystals
Kohji Abe; Hiroyuki Komagome; Tsuguhito Nakano; Takeshi Shigenari
Proceedings of the 12-th international Conferrence onthe Physics and Chemistry of Ice, Sapporo,, 397-401, May 2011, Peer-reviwed
Scientific journal, English - Direction of polarization of P and the dipole interaction in the ferroelectric phase of SrTi^18^O_3_
Takeshi Shigenari; Tsuguhito Nakano; Kohji Abe
Europhysics Letter, 94, 57001, May 2011, Peer-reviwed
Scientific journal, English - Raman spectra of proton ordered phase XI of ICE I. Translational vibrations below 350 cm(-1)
Kohji Abe; Takeshi Shigenari
JOURNAL OF CHEMICAL PHYSICS, AMER INST PHYSICS, 134, 10, 104506-1-11, Mar. 2011, Peer-reviwed, Polarized Raman spectra from single crystals of ice XI (proton ordered phase of ice Ih) were measured and assigned for the modes below 350 cm(-1) in the translational vibration region. In contrast to the proton disordered ice Ih, the spectra in ice XI show clear polarization dependence and several new peaks are observed. Most of the vibrational modes were successfully assigned by the simplified point mass model with the symmetry C-2v(12) (Cmc2(1)) and by the depolarization effect. In particular, LO-TO splitting of the mode near 240 cm(-1) was experimentally confirmed for the first time, which indicates that the long range force effect appears distinctly in ice XI. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551620]
Scientific journal, English - Formation of Grained Ferroelectric Domains in (SrTiO3)-O-18 Studied by Rayleigh - Mie Scattering
Tsuguhito Nakano; Shutaro Yamamoto; Takuji Noma; Yoichiro Tachibana; Yuki Katsumata; Kohji Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 416, 66-71, 2011, Peer-reviwed, Transmittances and scattering intensities were measured in (SrTiO3)-O-18 to clarify the process of the formations of grained ferroelectric domains. On cooling through T-c the transmittance starts to decrease and the scattering intensities starts to increase from a few degrees above T-c. These results suggest that polar nano clusters, which exist in even well above T-c, start to grow above T-c and on further cooling they percolate with other grains with the same polarization direction forming the grained ferroelectric domains. The size of the grained ferroelectric domains is estimated to reach a few hundreds of nanometer at very low temperatures.
Scientific journal, English - Why P in (SrTiO3)-O-18 is Not Parallel to [100](c) as Expected from the Slater Type Soft Mode?: Role of Rhombohedral Polar Clusters
Takeshi Shigenari; Tsuguhito Nakano; Kohji Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 416, 58-65, 2011, In spite of a number of studies on the ferroelectricity of the isotope exchanged (SrTiO3)-O-18, it has not been clarified yet why the spontaneous polarization P in the isotope exchanged (SrTiO3)-O-18 is not parallel to [100](c) as expected from the Slate mode but parallel to [110](c). In this paper it is shown that the dipole-dipole interaction between the rhombohedral polar clusters which exist from well above T-c is closely related to the formation of the P parallel to [110](c). The results are consistent with the appearance of the relaxational mode in the Raman spectra and suggest the existence of the order-disorder nature of this transition.
Scientific journal, English - Dual-frequency injection-locked nanosecond pulsed laser with arbitrary combination of two oscillation frequencies
Tsuguhito Nakano; Kenta Koizumi; Takashi Onose; Kohji Abe; Masayuki Katsuragawa
OPTICS EXPRESS, OPTICAL SOC AMER, 18, 25, 26409-26416, Dec. 2010, We report a dual-frequency injection-locked nanosecond pulsed laser oscillating at an arbitrary combination of two frequencies over the broad gain range of a Ti:sapphire laser. This performance is achieved by employing two techniques. One involves introducing two different modulation frequencies to discriminate electronically the error signals, which are used for locking the two seed frequencies to the forced oscillator. The other is a cavity design that enables us to sweep the cavity length without distorting the alignment or changing the spatial mode of the cavity. The difference frequencies in a pair of single-frequency nanosecond pulses can be selected continuously from less than 1 GHz to tens of THz without modifying the laser configuration. (C)2010 Optical Society of America
Scientific journal, English - コア・カリキュラム学習支援システムの効果的運用方法について
金長正彦; 大淵泰司; 浅井吉蔵; 阿部浩二; 鈴木 勝
大学の物理教育誌, 16, 1, 54-57, Mar. 2010, Peer-reviwed
Scientific journal, Japanese - Learning Support Based on Student Karte for the Core Curriculum
M. Kanenaga; Y. Ohfuti; K. Abe; M. Suzuki
INTERNATIONAL CONFERENCE ON PHYSICS EDUCATION, AMER INST PHYSICS, 1263, 204-207, 2010, Peer-reviwed, We started learning support by using a new e-Learning management system, Student Karte, for fundamental basic scholastic abilities to learn the core curriculum of Department of Applied Physics and Chemistry, UEC, in April 2008. The core curriculum is the bare bones of the students' future specialty. The characteristics of this system are the following: (1) The learning situation and the achievement level for related topics among all problems are kept in Student Karte; (2) Using Student Karte, students by themselves know whether they reach the necessary understanding of each topic; (3) Through Student Karte, students can easily understand the connection between topics. We adopted Student Karte to the course, Classical Mechanics, for freshmen. The usefulness is identified.
International conference proceedings, English - Effective Inclusion of e-Learning in a Subject of Physics Experiments: Introductory Electronics Laboratory
T. Okuno; K. Abe; N. Yamazaki; A. Ooe; K. Igarashi; S. Hayashi; M. Suzuki
INTERNATIONAL CONFERENCE ON PHYSICS EDUCATION, AMER INST PHYSICS, 1263, 130-+, 2010, Peer-reviwed, A Web-based e-Learning homework system was introduced in the undergraduate subject of the introductory electronics experiment; "Introductory Electronics Laboratory". This homework is appended to practical trainings and face-to-face guidance in the laboratory (blended-type e-Learning). The e-Learning is mainly prepared to teach basic electronics and to guide necessary apparatus before the practical training. The overall impression about this subject in students' questionnaires has improved from 3.5 for 2005/2006 (e-Learning not introduced) to 3.9 2007/2008 (e-Learning introduced) (5 for good, 3 for average, and 1 for bad). Students' understanding of the experiments has also improved from 3.43 for 2005/2006 to 3.45 for 2007/2008 (5, 4, 3, 2 for S, A, B, C grade). This subject is compulsory for all second-year students in our department (similar to 120 students). The e-Learning system in our case is considered to be effective especially for required subjects of experiments and large classes.
International conference proceedings, English - 学習者カルテに基づくコア・カリキュラムへの学習支援とその効果について
金長正彦; 大淵泰司; 浅井吉蔵; 阿部浩二; 鈴木勝
電気通信大学紀要, 22, 17-24, 2010, Peer-reviwed
Research institution, Japanese - 電子回路学実験（量子・物質工学科）におけるｅラーニング実施について
奥野剛史; 阿部浩二; 山崎典昌; 大家明広; 五十嵐清; 林茂雄
電気通信大学紀要, 電気通信大学, 21, 1-2, 59-66, 2009, Peer-reviwed, We have started e-Learning homework system in Introductory Electronics Laboratory at theDepartment of Applied Physics and Chemistry. WebClass in the Center for Developing e-Learningis used. Students are required to do this e-Learning homework before doing electronicsexperiments in the laboratory class. They would acquire basic knowledge on each theme of theexperiment every two weeks. This e-Learning homework system seemed to be effective andinterest most of the students. This is one of the subjects in "Learning support project for coresubjects by using Student Cards." This is also an example showing WebClass system from a user.
Research institution, Japanese - Significant softening of c(66) and hidden order parameter in the magnetic ordered state of La2-xCaxCoO4 (0.4 <= x <= 0.7)
K. Horigane; T. Kobayashi; M. Suzuki; K. Abe; K. Asai; J. Akimitsu
PHYSICAL REVIEW B, AMER PHYSICAL SOC, 78, 14, 144108-1,-6, Oct. 2008, Peer-reviwed, We have measured the longitudinal and transverse sound velocities of La2-xCaxCoO4 (0.4 <= x <= 0.7) propagating along [100], [110], and [001] from 200 K down to 3 K with a frequency of 10 MHz. It was found that c(66) shows a remarkable softening below Co2+ spin-ordering temperature T-N in the whole doping range, while c(11)-c(12)/2 exhibits a clear hardening below Co3+ spin-ordering temperature T-N2 only when x=0.5. To explain the observed anomaly, the Landau free energy for the La2-xCaxCoO4 system has been constructed, including the coupling energy between elastic strains and a two-dimensional order parameter (Q(1),Q(2)), having a spatial modulation along [110] or [<overline>1</overline>10]. We argued that this represents orbital order, and it is this order that leads to the softening of c(66).
Scientific journal, English - Photoluminescence properties of Eu3+-doped ZnO nanoneedles
Katsuyuki Ebisawa; Tsuyoshi Okuno; Kohji Abe
JAPANESE JOURNAL OF APPLIED PHYSICS, JAPAN SOC APPLIED PHYSICS, 47, 9, 7236-7238, Sep. 2008, Peer-reviwed, Eu3+-doped ZnO nanoneedles were fabricated by thermal evaporation. In order to include Eu in ZnO nanostructures, europium nitrate was used to produce starting droplets from which ZnO nanoneedles were grown. Photoluminescence spectra included a sharp blue peak corresponding to the ZnO band gap and a broad red band due to defect states. In addition, sharp intra-4f transitions of Eu3+ ions were observed. Energy transfer from the ZnO matrix to Eu3+ was also observed. Study of the photoluminescence excitation revealed absorption tail states below the ZnO band gap induced by the inclusion of Eu ions in the ZnO nanoneedles. The location of Eu ions was assumed to be near the surfaces of the ZnO nanoneedles.
Scientific journal, English - Crystal structure, magnetism, and dielectric properties of La1-xBixNi0.5Mn0.5O3
Yoshihiko Kobayashi; Masanori Shiozawa; Keisuke Sato; Kohji Abe; Kichizo Asai
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 77, 8, 084701.1-084701.8, Aug. 2008, Peer-reviwed, We have synthesized the polycrystalline La1-xBixNi0.5Mn0.5O3 for x = 0-0.9 by soft chemical synthesis, and investigated the crystal structure. and the magnetic and the dielectric properties. The crystal has a monoclinic P2(1)/c structure with centrosymmetry for 0 <= x <= 0.7. and has a monoclinic C2 structure with non-centrosymmetry for 0.8 <= x <= 0.9 at room temperature. The ferromagnetic Curie temperature (T-CM) decreases monotonically from 300 K at x = 0 to 150 K at x = 0.9, while the Ni2+- Mn4+ configuration is kept independent of Bi-content. For x >= 0.5. An anomalous increment of the dielectric constant with increasing temperature and the maximum in the dielectric loss accompanied with frequency dispersion were observed around 150 K, which is close to T-CM. However, no evidence showing, ferroelectric ordering was observed below 400 K. For x = 0.7, the increment of the dielectric constant induced by the magnetic field is 7% at T-CM at 9 T. The temperature and the magnetic field dependence of the dielectric properties is discussed based on Maxwell-Wagner model assuming an inhomogeneity of samples and a negative magnetoresistance.
Scientific journal, English - Origin of the Ferroelectricity in SrTi18O3 Studied by Raman Scattering
Takeshi Shigenari; Kohji Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 369, 117-126, 2008, Peer-reviwed, Isotope exchanged SrTi18O3(STO18) undergoes a ferroelectric transition at about Tc = 24 K. Its origin and mechanism have been investigated by many authors but even the direction of spontaneous polarization has not been clarified yet. In this paper from optical and Raman scattering studies, we report that the spontaneous polarizations are parallel to [1, 1,0]c, which is the crystal axes of the tetragonal phase. In Raman spectra, softening of TO modes are observed but the softening is not perfect. The displacement of soft mode is not parallel to the cubic axis [1, 0, 0]ccontrary to the expectation from Slater mode. Near Tc, a quasi-elastic mode appears which suggests the order-disorder nature of this transition. Although at temperatures far from Tc this transition is triggered by the soft TO mode, ferroelectricity in STO18 is a result of the percolation of polar clusters which exist already above Tc. The structure of STO18 below Tc is inhomogeneous mixture of the orthorhombic (C2v) ferroelectric domains with [image omitted] / / [110]c and [image omitted] / / [1[image omitted]0]c in the matrix of the tetragonal (D4h) structure.
Scientific journal, English - Comments on Raman Spectra of (SrTiO3)-O-18: Imperfect Softening and Intrinsic Inhomogeneity of the Ferroelectric Phase
Takeshi Shigenari; Kohji Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 375, 1, 138-147, 2008, Peer-reviwed, A peculiar nature of the ferroelectric phase transition of isotope exchanged (SrTiO3)-O-18(STO 18) are discussed by comparing three independent Raman studies which have been recently published. The results reported in a paper by the present authors (Phys. Rev. B 74, 174121 (2006)) are quite different from others as follows: (a) Contrary to the report by Takesada et al. (Phys. Rev. Lett. 96, 227602 (2006)), the perfect softening does not take place. Instead, a quasi-elastic mode appears near T-c indicating the order-disorder nature of STO 18; (b) Contrary to the report by Taniguchi et al. (Phys. Rev. Lett. 99, 017602 (2007)), the ferroelectric phase of STO18 is intrinsically inhomogeneous regardless of the isotope concentration. By comparison, it is shown that the conclusions in the latter two papers are not the case. The reason is that in these papers the spectra for only a single phonon propagation direction K-p were measured and analyzed without taking into account the consistency to the spectra for other K-p's. Contrary to other ordinary ferroelectric crystals, the transition in STO18 is peculiar because the ferroelectric domains are generated from the polar nano-region (PNR) and its percolation.
Scientific journal, English - Raman scattering study of proton ordered ice-XI single crystal
K. Abe; Y. Ootake; T. Shigenari
PHYSICS AND CHEMISTRY OF ICE, ROYAL SOC CHEMISTRY, 101-108, 2007, Peer-reviwed
International conference proceedings, English - Physical properties of C-60 intercalated graphite films
T. Nakahara; N. Hosomi; J. Taniguchi; M. Suzuki; T. Sato; K. Abe; D. Kuwahara; M. Ishikawa; M. Kato; K. Miura
INTERNATIONAL CONFERENCE ON SCIENCE OF FRICTION, IOP PUBLISHING LTD, 89, 012002, 2007, Peer-reviwed, Recently, Miura and Tsuda have synthesized C-60 intercalated graphite film (C-60/Gr) and reported that the C-60/Gr consists of alternating close-packed C-60 monolayers and graphite layers. They also found that its frictional force is minimal up to the loading force of 100 nN using AFM. [Miura K and Tsuda D 2005 e-J. Surf. Sci. Nanotech. 3 21] Thus, we have started to study the physical properties of C-60/Gr and carried out NMR, Raman scattering and specific heat measurements. These results suggest that C-60 in C-60/Gr rotates at room temperature.
International conference proceedings, English - Raman scattering study of proton ordered ice-XI single crystal
K. Abe; Y. Ootake; T. Shigenari
PHYSICS AND CHEMISTRY OF ICE, ROYAL SOC CHEMISTRY, 311, 101-108, 2007, Peer-reviwed
International conference proceedings, English - Raman spectra of the ferroelectric phase of (SrTiO3)-O-18: Symmetry and domains below T-c and the origin of the phase transition
Takeshi Shigenari; Kohji Abe; Tomohiko Takemoto; Osamu Sanaka; Takashi Akaike; Yoshihide Sakai; Ruiping Wang; Mitsuru Itoh
PHYSICAL REVIEW B, AMER PHYSICAL SOC, 74, 17, 174121, Nov. 2006, Peer-reviwed, Polarized Raman spectra of isotope substituted (SrTiO3)-O-18 (STO18) crystals were studied in the ferroelectric phase below T-c=24.5 K. Samples were confirmed to be a single domain in the tetragonal phase (T-c < T < T-0=108 K). Raman spectra in various phonon propagation directions K-p were found to satisfy the selection rules for orthorhombic C-2v symmetry with the spontaneous polarization P parallel to the tetragonal axes, either [110](c) or [110](c). Below T-c, STO18 is inhomogeneous and consists of a number of small ferroelectric domains as well as remnants of the tetragonal structure. Soft TO modes originated from the lowest Gamma(15) mode in cubic phase were observed at 20 and 12.5 cm(-1). On heating, these modes soften but do not freeze at T-c. Near T-c, a quasielastic scattering component appears and its intensity critically increases. Although for temperatures far from T-c, the transition is promoted by the softening of the TO modes, the appearance of P at T-c cannot be attributed to the freezing of Slater mode since P is not parallel to the cubic axis [100](c). Origin of the relaxational mode near T-c and the direction of P are discussed in terms of the orientational ordering of locally polarized clusters which already exist above T-c. These results indicate that the phase transition in STO18 is a peculiar transition and has both order-disorder and displacive nature.
Scientific journal, English - Character of the incommensurate modulation and the problem of light scattering in quartz near the alpha <->beta transition
TA Aslanyan; T Shigenari; K Abe; DA Semagin
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 73, 15, 153101, Apr. 2006, Peer-reviwed, It is shown that the observed incommensurate structure near the alpha <->beta transition in quartz is a pure transverse acoustic modulation without any optic mode displacements component. Such a long-period acoustic modulation cannot be responsible for the observed light scattering in quartz, contrary to the interpretation by Dolino.
Scientific journal, English - Raman spectra of the ferroelectric phase of Sr Ti18 O3: Symmetry and domains below Tc and the origin of the phase transition
Takeshi Shigenari; Kohji Abe; Tomohiko Takemoto; Osamu Sanaka; Takashi Akaike; Yoshihide Sakai; Ruiping Wang; Mitsuru Itoh
Physical Review B - Condensed Matter and Materials Physics, American Physical Society, 74, 17, 2006, Polarized Raman spectra of isotope substituted Sr Ti18 O3 (STO18) crystals were studied in the ferroelectric phase below Tc =24.5 K. Samples were confirmed to be a single domain in the tetragonal phase (Tc <
T<
T0 =108 K). Raman spectra in various phonon propagation directions K p were found to satisfy the selection rules for orthorhombic C2v symmetry with the spontaneous polarization P parallel to the tetragonal axes, either [110]c or [1 1̄ 0]c. Below Tc, STO18 is inhomogeneous and consists of a number of small ferroelectric domains as well as remnants of the tetragonal structure. Soft TO modes originated from the lowest Γ15 mode in cubic phase were observed at 20 and 12.5 cm-1. On heating, these modes soften but do not freeze at Tc. Near Tc, a quasielastic scattering component appears and its intensity critically increases. Although for temperatures far from Tc, the transition is promoted by the softening of the TO modes, the appearance of P at Tc cannot be attributed to the freezing of Slater mode since P is not parallel to the cubic axis [100]c. Origin of the relaxational mode near Tc and the direction of P are discussed in terms of the orientational ordering of locally polarized clusters which already exist above Tc. These results indicate that the phase transition in STO18 is a peculiar transition and has both order-disorder and displacive nature. © 2006 The American Physical Society.
Scientific journal, English - Dielectric and fluorescence study on phase transitions in liquid crystal 5CB and 8CB
K Abe; A Usami; K Ishida; Y Fukushima; T Shigenari
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 46, 1, 220-223, Jan. 2005, Peer-reviwed, Successive phase transitions, isotropic(l)-nematic(N)-crystal(C) of 5CB (pentyl cyanobiphenyl) and I-N-smectic(Sm)-C of 8CB (octyl cyanobiphenyl) were studied by dielectric measurement and time-resolved fluorescence spectroscopy. Dielectric constants in 5CB and 8CB are very similar and show a considerable change at the I-N transition and an abrupt decrease at the crystallization point. In fluorescence spectra, a broad and intense band from excimers (dimers in the excited state) and a weak band from monomers arc observed at around at 405 nm and 350 nm, respectively. The temperature dependence of fluorescence spectra and lifetime show a gradual change before the melting point as a precursor of the first-order transition, while only little change was observed at the N-I transition.
Scientific journal, English - Raman spectra of proton ordered XI phase ice crystal
K Abe; T Miasa; Y Ohtake; K Nakano; M Nakajima; H Yamamoto; T Shigenari
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 46, 1, 300-302, Jan. 2005, Peer-reviwed, Proton ordering phase transition of ice crystal was studied by Raman spectroscopy. The difference of the vibrational modes between 1h and XI phase were detected for the first time in the translation region and in the libration region. Below T-c(= 72K), in the translation region a new intense peak was observed at 236 cm(-1) and the peak at 315 cm(-1) in 1h phase shifted to 325 cm-1. In the libration region several new peaks were observed. Assignments of these modes are discussed from the polarization dependence.
Scientific journal, English - Effects of electric field on Raman spectra in (SrTiO3)-O-16 and (SrTiO3)-O-18
K Abe; T Takemoto; O Sanaka; T Akaike; T Shigenari; R Wang; M Itoh
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 46, 1, 224-227, Jan. 2005, Peer-reviwed, Effects of an external electric field on Raman spectra were studied in oxygen-isotope-substituted (SrTiO3)-O-18 (STO18). Significant frequency shifts and an increase of the intensities were observed above and below the ferroelectric transition temperature T-c = 23 K. Despite the clear difference in normal Raman spectra, at low temperatures, the effect of an electric field on the ferroelectric soft mode is similar to that for STO16, suggesting that in STO18 the soft mode remains very sensitive to the electric field.
Scientific journal, English - Numerical analysis of atomic motion in the incommensurate phase of quartz (SiO2) in the vicinity of phase transition
DA Semagin; T Shigenari; SV Dmitriev; K Abe
PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL. 1, NO. 11, WILEY-V C H VERLAG GMBH, 1, 11, 3057-3060, 2004, Peer-reviwed, In order to find out the details of microscopic structure of incommensurate (IQ phase in quartz, we studied numerically the time correlation in the atomic motion and the static pattern of the structure at different temperatures. The analysis of temperature dependence of the numerical data revealed several important facts, which strongly support the recent theoretical assumptions concerning the possibility to observe IC phase in quartz and concerning geometrical interpretation of the neutron diffraction pattern. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
International conference proceedings, English - Molecular and lattice dynamical study on modulated structures in quartz
SV Dmitriev; DA Semagin; T Shigenari; K Abe; M Nagamine; TA Aslanyan
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 68, 5, 052101, Aug. 2003, Peer-reviwed, It is shown that atomistic simulations using the Tsuneyuki potential for silica (SiO2) correctly reproduce the major experimentally observed properties of the incommensurate (INC) phases in quartz, such as the phase sequence, the direction of the modulation, the coupling of the soft optic with the TA modes, the dispersion surface anisotropy, the stress dependence of the transition temperature, etc. The obtained phase diagram is topologically equivalent to those predicted from general INC phase theories. At high temperature, our results give a short period modulation with kapproximate tob/3 as predicted by the new model for the origin of INC phase in quartz [Aslanyan , J. Phys.; Condens. Matter 10, 4565 (1998); 10, 4577 (1998)].
Scientific journal, English - Stable modulated and homogeneous structures of quartz (SiO2): Analysis of eigen-modes near phase transition points
DA Semagin; SV Dmitriev; K Abe; T Shigenari
FERROELECTRICS, TAYLOR & FRANCIS LTD, 283, 141-147, 2003, Peer-reviwed, We obtain a variety of modulated and homogeneous phases of quartz, stable at zero-temperature, by means of relaxational and lattice dynamics calculation. The interatomic interaction is given by the Tsuneyuki pairwise potential. The order of appearance of the phases resembles the experimentally observed order. The essential role of the potential profile is obviated. The kinetics of phase transformations in quartz is illustrated by the analysis of dispersion curves and eigenvectors, which show some peculiarities near transition points.
Scientific journal, English - Raman spectra of ferroelectric soft mode in SrTiO3: Effect of electric field
T Shigenari; K Abe; K Yamashita; T Takemoto; RP Wang; M Itoh
FERROELECTRICS, TAYLOR & FRANCIS LTD, 285, 415-422, 2003, Peer-reviwed, Raman spectra in SrTiO3 single crystals were measured. In the ferroelectric phase below T-c = 24 K in (SrTiO3)-O-18, two modes were observed to soften on heating towards T-c = 24 K. These modes are assigned as the two split components of the ferroelectric soft E-u-symmetry mode in the tetragonal phase above T-c.
The existence of the soft modes suggests that the ferroelectricity in (SrTiO3)-O-18 is intrinsic in nature. In (SrTiO3)-O-16, external electric field significantly increases the Raman intensity of the E-u mode and induces the interaction with different symmetry modes. In the ferroelectric phase of (SrTiO3)-O-18, the electric field has much smaller influence on the soft modes.
Scientific journal, English - Second-order type symmetry breaking preceding the first order incommensurate-to-alpha phase transition in quartz
DA Semagin; SV Dmitriev; K Abe; T Shigenari
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY, INTERPERIODICA, 77, S30-S33, 2003, A realistic subsequence of phase transformations in quartz is obtained by means of relaxational and lattice dynamics calculation. The interatomic interaction is described by the Tsuneyuki pairwise potential. An unidentified modulated phase with broken symmetry is found between usual modulated and alpha phases. The kinetics of phase transformations in quartz are illustrated by the analysis of dispersion curves and eigenvectors.
Scientific journal, English - Strong first order phase transitions studied by Raman and fluorescence spectroscopy
T Shigenari; K Abe
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY, INTERPERIODICA, 77, S40-S46, 2003, It is shown that the measurement of fluorescence decay rate is a sensitive probe for the detection of the precursor in strongly first-order phase transitions. Experimental results are given for the structural phase transition and the melting transition in molecular crystals. The critical decrease of the fluorescence lifetime on approaching the transition temperature is attributed to large fluctuations in the displacement of atoms that are localized spatially as well as temporarily. For the proton-ordering transition in ice, which is a different type of strong first order transition, Raman spectra and the fluorescence lifetime variation were observed after a long annealing process for nucleation and the growth of the ordered phase.
Scientific journal, English - Elastically hinged molecule model: Discrete medium and continuum
SV Dmitriev; H Jimbo; K Abe; T Shigenari
FERROELECTRICS, TAYLOR & FRANCIS LTD, 267, 361-366, 2002, Peer-reviwed, We consider the microscopic models of crystals containing finite size particles with rotational degrees of freedom. New physical effects due to the rotational degrees of freedom are discussed. We demonstrate that the continuum approximations for these models lead to the so-called micropolar elasticity theory. Conditions when the micropolar medium can be reduced to the usual elastic medium are described.
Scientific journal, English - MD calculation for modulated phase in quartz
DA Semagin; SV Dmitriev; K Abe; T Shigenari; T Aslanyan
FERROELECTRICS, TAYLOR & FRANCIS LTD, 268, 227-232, 2002, Peer-reviwed, We perform the Parinello-Rahman MD study of modulated phases in quartz. In the temperature interval of several ten degrees between alpha- and beta-phases the three-periodic 3q-modulated phase was found. The results are used to discuss the recently proposed new interpretation of the incommensurate modulation in quartz.
Scientific journal, English - On the light scattering in some crystals with triple-period commensurate phases
TA Aslanyan; T Shigenari; K Abe
FERROELECTRICS, TAYLOR & FRANCIS LTD, 272, 2097-2103, 2002, Peer-reviwed, It is shown that a depolarized light scattering should be observed in the triple period phase of K2SeO4 and other crystals of that family. The light scattering in form of a narrow central peak is induced by the new symmetry mode, which appears in this phase, and may be interpreted as a phase fluctuation of the modulated structure.
Scientific journal, English - Raman spectra in ferroelectric (SrTiO3)-O-18
K Abe; K Yamashita; Y Tomita; T Shigenari; RP Wang; M Itoh
FERROELECTRICS, TAYLOR & FRANCIS LTD, 272, 2147-2152, 2002, Peer-reviwed, Raman spectra in a ferroelectrics SrTiO3 crystal in which 84% O-16 is replaced by the isotope O-18 were studied. Dielectric measurement shows that the sample undergoes a ferroelectric phase transition at 24K. Softening of a peak at 11 cm(-1) was found on heating to the transition temperature T-c. New peaks also appear at 170cm(-1) and 545cm(-1) below 24K as the result of the condensation of the zone center F-1u modes. Analyzing the spectra in different scattering geometries for the twinned sample, we tentatively assigned the phonon modes assuming that the ferroelectric phase has the symmetry C-2v with the polar axis perpendicular to the tetragonal c axis.
Scientific journal, English - Excited states as a probe of structural phase transitions in polyphenyl crystals
T Shigenari; K Abe; M Mizuno; K Ishida; T Suzuki; Y Fukushima; T Narisawa
FERROELECTRICS, TAYLOR & FRANCIS LTD, 272, 2153-2158, 2002, Peer-reviwed, Phase transitions in biphenyl and p-terphenyl crystals were studied by the laser induced fluorescence and the absorption spectroscopy. In biphenyl, besides the intrinsic band starting from a false zero-phonon peak at 302.5nm, an excimer-like broad band appeared at about 480nm. The fluorescence decay curve changes near T-c=17K and 40K, since the fluctuations of tortional vibration near T-c have an influence on the energy transfer rate from the intrinsic excited state to the excimer-like state. The deviation from the Urbach-rule below T-1 = 40K in the absorption tail of biphenyl is also attributed to the tortional amplitude mode. In p-terphenyl, unlike the biphenyl case, sharp absorption peaks to the tortional levels in the excited state appears up to 50K and the fluorescence intensities gradually change with temperature in a characteristic way.
Scientific journal, English - Elastically Hinged Molecule Model: Relation Between Discrete Media and Continuum
S.V. Dmitoriev; H.Jimbo; K. Abe; T.Shigenari
Abstrct, 32, Sep. 2001
International conference proceedings, English - Debye-Waller factor due to the phase fluctuation in the incommensurate phase: strange behavior in SiO2
T.Shigenari; K.Abe; S.V.Dmitriev; T.A.Aslanyan
Abstract, 230, Sep. 2001
International conference proceedings, English - MD calculation for Modulated Phase in Quartz
D.A.Semagin; S. V. Dmitriev; K.Abe; T.Shigenari; T.A.Aslanyan
Abstract, 63, Sep. 2001
International conference proceedings, English - Low frequency Raman Spectra and the Incommensurate Phase in Quartz
T.Shigenari; K.Abe; M.Yajima; M. Nagamine; S.V. Dmitriev; T.A.Aslanyan
Abstract, 156, Sep. 2001
International conference proceedings, English - Raman Spectra of GPI(Glycine Phosphite) single Crystal.
K.Abe,L.Y.Wang; R.Sobiestianskas; K.Yamashita; T.Shigenari
Abstract, 171, Sep. 2001
International conference proceedings, English - Raman Spectra in the Proton Ordered XI Phase of KOH doped Ice Single Crystal.
K.Abe; M.Nakajima; H.Yamamoto; K. Nakano; T.Shigenari
Abstract, 171, Sep. 2001
International conference proceedings, English - On the Light Scattring in Some Crystals with Triple-Period Commensurate.
T.A.Aslanyan; T.Shigenari; K.Abe
Abstract, 176, Sep. 2001
International conference proceedings, English - Raman Spectra in Ferroelectric SrTi18O3: Effect of Electric Field.
K.Abe; K.Yamashita; Y.Tomita; T.Shigenari; R.Wang; M.Itoh
Abstract, 179, Sep. 2001
International conference proceedings, English - Excited State as a Probe of Structural Phase Transitions in PolyPhenyl Crystals.
T.Shigenari; K.Abe; M.Mizuno; T.Suzuki; T.Narisawa
Abstract, 179, Sep. 2001
International conference proceedings, English - Periodic metastable structures in the discrete φ4 model
S.V. Dmitriev; H.Jimbo; K. Abe; T.Shigenari
Phys.Rev. E，, 64, 036202-1, Aug. 2001
Scientific journal, English - Poisson ratio beyond the limits of the elasticity theory
SV Dmitriev; T Shigenari; K Abe
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 70, 5, 1431-1432, May 2001, Peer-reviwed
Scientific journal, English - Simulation of modulated structures in quartz
SV Dmitriev; M Yajima; Y Makita; DA Semagin; K Abe; T Shigenari
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 70, 2, 428-436, Feb. 2001, Peer-reviwed, We report the results of molecular-dynamics calculation of equilibrium modulated phases of quartz in the vicinity of pressure induced alpha - beta transition. A numerical method suitable for simulation of modulated phases in the vicinity of transition point was developed. The phase diagram with respect to the unit cell deformations was obtained from the pairwise interatomic potentials by [Tsuneyuki et al.: Phys. Rev. Lett. 61 (1988) 869]. The results show that the modulated structures with various wavevectors appear between alpha- and beta -phases suggesting that the softening may occur at any point on the Sigma line in the Brillouin zone and that a structure with large wavevector seems to be more probable than one with a small wavevector.
Scientific journal, English - Raman spectrum and the origin of phase transitions in quartz
T Shigenari; K Abe; SV Dmitriev; M Yajima; M Nagamine; D Semagin; TA Aslanyan
FERROELECTRICS, TAYLOR & FRANCIS LTD, 259, 1-4, 103-108, 2001, Raman scattering and lattice dynamical calculations were performed to discuss the origin of the incommensurate(INC) phase in quartz. A broad low frequency mode was found to exist in a wide temperature range. Its intensity significantly increase in beta phase on cooling towards the transition temperature. The lattice dynamical calculation suggests that this mode reflects the increase of the phonon density of TA-mode along the E line. The results are consistent with the new model by Aslanyan et al. (J.Phys.Condens.Matter,10,4575(1998).) which claims that the INC modulation would occur first near b/3 rather than close to Gamma point and that there exists another commensurate phase just above the a phase.
Scientific journal, English - Elastically hinged molecule model in physics of ferroelectric materials
SV Dmitriev; DA Semagin; K Abe; AA Vasiliev; T Shigenari
FERROELECTRICS, TAYLOR & FRANCIS LTD, 262, 1-4, 1027-1032, 2001, The microscopic model of a crystal consisting of finite size particles is proved to be more realistic for many ferroelectric crystals than the models with pointwise particles. Two ideas naturally appeared when deriving the continuum approximations for this model. The first one is to consider a crystal as micropolar media, which is the continuum analog for the microscopic model with particles having rotational degrees of freedom. The second idea is to use the many-field approximation. A particular problem of the negative Poisson ratio, having no place in a model with pointwise particles, is also discussed. Finally, a new mechanism of the lock-in transition in a crystal supporting the incommensurate phase is offered.
Scientific journal, English - Elastically Hinged Molecule Model: Rrelation between discreet Media and Continuum
S.V.Dmitriev; N.Jinbo; K.Abe; T.Shigenari
Abstract, 3-7, 2001
International conference proceedings, English - Elastically hinged molecule model in physics of ferroelectric materials
SV Dmitriev; DA Semagin; K Abe; AA Vasiliev; T Shigenari
FERROELECTRICS, TAYLOR & FRANCIS LTD, 262, 1-4, 1027-1032, 2001, Peer-reviwed, The microscopic model of a crystal consisting of finite size particles is proved to be more realistic for many ferroelectric crystals than the models with pointwise particles. Two ideas naturally appeared when deriving the continuum approximations for this model. The first one is to consider a crystal as micropolar media, which is the continuum analog for the microscopic model with particles having rotational degrees of freedom. The second idea is to use the many-field approximation. A particular problem of the negative Poisson ratio, having no place in a model with pointwise particles, is also discussed. Finally, a new mechanism of the lock-in transition in a crystal supporting the incommensurate phase is offered.
Scientific journal, English - Raman spectrum and the origin of phase transitions in quartz
T Shigenari; K Abe; SV Dmitriev; M Yajima; M Nagamine; D Semagin; TA Aslanyan
FERROELECTRICS, TAYLOR & FRANCIS LTD, 259, 1-4, 103-108, 2001, Peer-reviwed, Raman scattering and lattice dynamical calculations were performed to discuss the origin of the incommensurate(INC) phase in quartz. A broad low frequency mode was found to exist in a wide temperature range. Its intensity significantly increase in beta phase on cooling towards the transition temperature. The lattice dynamical calculation suggests that this mode reflects the increase of the phonon density of TA-mode along the E line. The results are consistent with the new model by Aslanyan et al. (J.Phys.Condens.Matter,10,4575(1998).) which claims that the INC modulation would occur first near b/3 rather than close to Gamma point and that there exists another commensurate phase just above the a phase.
Scientific journal, English - Domain wall solutions for EHM model of crystal: structures with period multiple of four
SV Dmitriev; K Abe; T Shigenari
PHYSICA D, ELSEVIER SCIENCE BV, 147, 1-2, 122-134, Dec. 2000, Peer-reviwed, For a one-dimensional discrete model of a crystal the form of a moving domain wall in the structure with period multiple of four was derived in the constant amplitude approximation. The energy of the carrying commensurate structure, the width and the energy of the domain wall were expressed in terms of the amplitudes of Fourier harmonics of the carrying commensurate structure. With the use of the result by Ishibashi, the relation between different solutions was established. The applicability and the accuracy of the solutions were tested by comparing them with the numerically obtained exact solutions. (C) 2000 Elsevier Science B.V. All rights reserved.
Scientific journal, English - Phonon emission from a discrete sine-Gordon breather
SV Dmitriev; T Shigenari; K Abe; AA Vasiliev; AE Miroshnichenko
COMPUTATIONAL MATERIALS SCIENCE, ELSEVIER SCIENCE BV, 18, 3-4, 303-307, Sep. 2000, Peer-reviwed, Phonon emission from a large-amplitude discrete sine-Gordon breather was studied numerically for a small degree of discreteness. In contrast to the case of highly discrete system investigated by Boesch and Peyrard (Phys. Rev. B 43 (1991) 8491), it was found that the resonance between the breather's oscillation and the phonons of the lower phonon band edge (kappa = 0) takes place for a small degree of discreteness. (C) 2000 Elsevier Science B.V. All rights reserved.
Scientific journal, English - Temperature dependence of luminescence lifetime in Cu2O
N Harukawa; S Murakami; S Tamon; S Ijuin; A Ohmori; K Abe; T Shigenari
JOURNAL OF LUMINESCENCE, ELSEVIER SCIENCE BV, 87-9, 1231-1233, May 2000, Peer-reviwed, The temperature dependence of the luminescence lifetime at 910 nm (so-called p-luminescence related to the presence of excitons and copper vacancies) was investigated. At low temperatures, the lifetime gradually increases up to about 130 K, but the decay curve suddenly splits to the double exponential form for higher temperatures. The strange temperature dependence was analyzed based on a model in which the oxygen vacancies act as the reservoir for the beta-luminescence. The results and other observations suggest that Cu vacancy level should not be so deep (0.55 eV) as currently believed. (C) 2000 Published by Elsevier Science B.V. All rights reserved.
Scientific journal, English - Photoacoutic and photoluminescence characterisation of highly porous polycrystalline TiO2 electrodes made by chemical synthesis
T. Toyoda; T. Hayakawa; K. Abe; T. Shigenari; Q. Shen
J. Luminescence, 87-89, 1237-1239, May 2000, Peer-reviwed
Scientific journal, English - Structural phase transitions of polyphenyl crystals studied by fluorescence and absorption spectroscopy
T Suzuki; G Kudo; K Nukui; M Mizuno; K Abe; T Shigenari
JOURNAL OF LUMINESCENCE, ELSEVIER SCIENCE BV, 87-9, 623-625, May 2000, Peer-reviwed, Structural phase transitions in biphenyl and p-terphenyl crystals are studied by fluorescence and absorption measurement. In biphenyl, the fluorescence decay curves vary near the transition temperature T-c = 40 K. It is attributed to the increase of the excimer-like acceptor near T-c. The analysis of the absorption band tail shows that the tortional soft mode at 25 cm(-1) is the main origin of the deviation from the simple Urbach-rule below T-c. In p-terphenyl, the sharp peaks due to tortional modes in the excited state are observed near the absorption edge and they disappear above similar to 50 K. (C) 2000 Elsevier Science B.V. All rights reserved.
Scientific journal, English - Photoluminescence and photoacoustic investigations of the photodarkening effect in CdSxSe1-x nanocrystal-doped glasses
Q Shen; K Abe; T Shigenari; T Toyoda
JOURNAL OF LUMINESCENCE, ELSEVIER SCIENCE BV, 87-9, 444-446, May 2000, Peer-reviwed, Photoluminescence (PL) and Photoacoustic (PA) techniques were applied to study photodarkening phenomena in CdSxSe1-x (x = 0.26) nanocrystal-doped glasses. We found that the PL intensities decreased greatly after undergoing darkening and the PA signal intensities became higher( similar to 3-6%). The PA signal intensities exponentially decay below the fundamental absorption edges, of which the logarithmic slope decreases after undergoing photodarkening. This implies an increase of the effective number of the surface states of the CdSxSe1-x nanocrystals due to darkening. These results can be explained well by a model according to which nonradiative recombination centers were activated at the semiconductor nanocrystal and glass interfaces by the darkening. (C) 2000 Published by Elsevier Science B.V. All rights reserved.
Scientific journal, English - Kink-breather solution in the weakly discrete Frenkel-Kontorova model
SV Dmitriev; T Miyauchi; K Abe; T Shigenari
PHYSICAL REVIEW E, AMERICAN PHYSICAL SOC, 61, 5, 5880-5885, May 2000, Peer-reviwed, The discrete Frenkel-Kontorova model, having the sine-Gordon equation as the continuous analog, was investigated numerically at a small degree of discreteness. Interaction between a kink and a breather in a discrete system was compared with the exact three-soliton solution to the continuous sine-Gordon equation. Nontrivial effects of discreteness were found numerically. One is that a kink and a breather in the discrete system are mutually attractive quasiparticles, so they can be regarded as a three-soliton oscillatory system. The other is the energy exchange between a kink and a breather when their collision takes place in a vicinity of a separatrix solution to the continuous sine-Gordon equation. We have estimated numerically the kink-breather binding energy E-B and the maximum possible exchange energy EE for different breather frequencies omega The results suggest that there is a threshold breather frequency for the "spontaneous" breaking up of the three-soliton oscillatory system into a kink and a breather moving in opposite directions.
Scientific journal, English - 弾性ヒンジ分子モデルによる不整合相転移のシミュレーション
S.V.Dmitriev; 阿部浩二; 重成武
日本物理学会誌, 日本物理学会, 55, 2, 113-117, Feb. 2000, Peer-reviwed, 多くの誘電体結晶に見られる不整合相転移について,新しいモデルを用いて計算機シミュレーションの研究を行った.このモデルは圧力,温度をパラメータと見なせる点で物理的に捉えやすく,任意周期の変調構造に対する安定性とそのダイナミクスを調べることができる.特に現象論では扱いにくい,整合-不整合相間の1次相転移におけるドメイン構造の生成消滅過程が理解できる.
Scientific journal, Japanese - Elastically hinged molecule model for computer simulation of incommensurate phase in crystals
SV Dmitriev; K Abe; T Shigenari
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 237, 1-4, 321-328, 2000, The results of analytical and numerical studies of a microscopic model of crystal with modulated structures are reviewed. Thr relation between our model and previous models is established. Some new phenomena related to the hysteresis of the lock-in transition are discussed.
Scientific journal, English - Structural phase transitions of polyphenyl crystals studied by fluorescence and absorption spectroscopy
T. Suzuki; G. Kudo; K. Nukui; M. Mizuno; K. Abe; T. Shigenari
Journal of Luminescence, Elsevier Science Publishers B.V., 87, 623-625, 2000, Structural phase transitions in biphenyl and p-terphenyl crystals are studied by fluorescence and absorption measurement. In biphenyl, the fluorescence decay curves vary near the transition temperature Tc = 40 K. It is attributed to the increase of the excimer-like acceptor near Tc. The analysis of the absorption band tail shows that the tortional soft mode at 25 cm-1 is the main origin of the deviation from the simple Urbach-rule below Tc. In p-terphenyl, the sharp peaks due to tortional modes in the excited state are observed near the absorption edge and they disappear above approx. 50 K.
Scientific journal, English - Simulation of pressure induced phase transition and modulated structures of quartz
SV Dmitriev; M Yajima; Y Makita; K Abe; T Shigenari
PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 138, 243-244, 2000, Peer-reviwed, In the vicinity of alpha <-> beta transition in quartz there exists an incommensurate phase. We perform numerical calculations to obtain the phase diagram of quartz and estimate the period of modulation. The results show that modulation phase with a short period is preferable in contrast to the currently accepted interpretation of incommensurate phase in quartz.
Scientific journal, English - Thermally activated generation, motion and annihilation of kinks in the Frenkel-Kontorova chain
SV Dmitriev; M Itoh; M Shinohara; K Abe; T Shigenari
PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 138, 574-575, 2000, Peer-reviwed, Thermalized Frenkel-Kontorova chain was studied numerically at different temperatures and degrees of discreteness. In our calculations, highly discrete and weakly discrete systems were found to show different behavior. It may be due to the fact that in a highly discrete chain, in contrast to a weakly discrete one, not only the continuous sine-Gordon breathers but also the discrete breathers can exist. At the! present stage, however, we cannot separate the contributions of the different kinds of localized modes.
Scientific journal, English - Elastically hinged molecule model for computer simulation of incommensurate phase in crystals
SV Dmitriev; K Abe; T Shigenari
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 237, 1-4, 321-328, 2000, Peer-reviwed, The results of analytical and numerical studies of a microscopic model of crystal with modulated structures are reviewed. Thr relation between our model and previous models is established. Some new phenomena related to the hysteresis of the lock-in transition are discussed.
Scientific journal, English - Raman scattering at the proton ordering phase transition in ice crystal
K Abe; K Ishii; M Nakajima; H Fukuda; T Shigenari
FERROELECTRICS, TAYLOR & FRANCIS LTD, 239, 1-4, 871-878, 2000, Peer-reviwed, The proton ordering I-h-XI phase transition at 72K in KOH doped ice single crystal was studied by Raman Spectroscopy. The spectral changes related to the proton ordering phase transition in the translational region were observed reproducibly. In XI ordered phase the intensity of the peak at 230cm(-1) becomes strong and two new peaks appear at 237cm(-1) and 324cm(-1), while the broad component between 250cm(-1) and 310cm(-1) becomes weak. The new lines at 237cm(-1) and 324cm(-1) are assigned as the LO-modes which are enhanced by the depolarization field due to the ferroelectric ordering of water molecules in ice.
Scientific journal, English - Simulation of pressure induced phase transition and modulated structures of quartz
SV Dmitriev; M Yajima; Y Makita; K Abe; T Shigenari
PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 138, 138, 243-244, 2000, Peer-reviwed, In the vicinity of alpha <-> beta transition in quartz there exists an incommensurate phase. We perform numerical calculations to obtain the phase diagram of quartz and estimate the period of modulation. The results show that modulation phase with a short period is preferable in contrast to the currently accepted interpretation of incommensurate phase in quartz.
Scientific journal, English - Thermally activated generation, motion and annihilation of kinks in the Frenkel-Kontorova chain
SV Dmitriev; M Itoh; M Shinohara; K Abe; T Shigenari
PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 138, 138, 574-575, 2000, Peer-reviwed, Thermalized Frenkel-Kontorova chain was studied numerically at different temperatures and degrees of discreteness. In our calculations, highly discrete and weakly discrete systems were found to show different behavior. It may be due to the fact that in a highly discrete chain, in contrast to a weakly discrete one, not only the continuous sine-Gordon breathers but also the discrete breathers can exist. At the! present stage, however, we cannot separate the contributions of the different kinds of localized modes.
Scientific journal, English - A new interpretation of incommensurate phase of quartz
T Shigenari; SV Dmitriev; K Abe; Y Makita; M Yajima; TA Aslanyan
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 240, 1-4, 1413-1420, 2000, Peer-reviwed, Optical and lattice dynamical studies were performed on the incommensurate(IC) phase in quartz. There are two different regions (fog- and m- zone) near the boundary between alpha and IC phase. The birefringence in the fog-zone was found to be much larger than that expected from the currently accepted model. The lattice dynamical calculation using the Tsuneyuki potential (Phys. Rev. Lett., 61, 869(1988)), revealed that a stable modulated structure with a short period exists between alpha and beta phases. Both results qualitatively agree with the new model recently proposed by Aslanyan et al. (J. Phys. Condens. Matter, 10, 4575(1998)) which assumes that the softening would occur near b/3 rather than close to Gamma point.
Scientific journal, English - 弾性ヒンジ分子モデルによる不整合相転移のシュミレーション
S. V. Dmitriev; 阿部浩二; 重成 武
日本物理学会誌(最近の研究から), 55, 2, 113-117, 2000
Japanese - Nonlinear phonon-phonon interaction dynamics in alpha-quartz studied by time-resolved spectroscopy
Y. Tsujimi; K. Sato; M. Kobayashi; S. Yoshioka; M. Kasahara; T. Yagi; T. Shigenari; K. Abe
J. Korean Phys. Soc., 35, S1392-S1395, Nov. 1999, Peer-reviwed
Scientific journal, English - Reply to the comment on 'Inhomogeneities and birefringence in quartz'
TA Aslanyan; T Shigenari; K Abe
JOURNAL OF PHYSICS-CONDENSED MATTER, IOP PUBLISHING LTD, 11, 41, 8175-8176, Oct. 1999, Peer-reviwed, The ferroelasticity effect of the incommensurate phase of quartz is discussed. It is pointed out that the effect discussed in the paper by Saint-Gregoire et al (Saint-Gregoire P, Snoeck E, Roucau C, Luk'yanchuk 1 and Janovec V 1996 JETP Lett. 64 410) is negligibly small, and cannot explain the anomalous observations near the alpha <-> beta transition in quartz.
Scientific journal, English - Photoacoustic and photoluminescence characterization of highly porous polycrystalline TiO_2_ electrodes made by chemical synthesis
T. Toyoda; T. Hayakawa; K. Abe; T. Shigenari; Q. Shen
1999 Int. Conf. Luminescence and Optical Spectroscopy of Condensed Matter（Osaka, Japan 23-27.Aug.1999），Collected Abstracts, 176, Aug. 1999
International conference proceedings, English - Photoluminescence and photoacoustic investigations of the photodarkening effect in CdS_x_Se_1-x_ nanocrystal-doped glasses
Q. Shen; K. Abe; T. Shigenari; T. Toyoda
1999 Int. Conf. Luminescence and Optical Spectroscopy of Condensed Matter（Osaka, Japan 23-27.Aug.1999），Collected Abstracts, 122, Aug. 1999
International conference proceedings, English - Influence of chemical etching for porous silicon of photoacoustic, photoluminescence, and photoluminescence excitation spectra.
T. Toyoda; T. Takahasi; M. Yamamuro; K. Abe; T. Shigenari; Q. Shen
1999 Int. Conf. Luminescence and Optical Spectroscopy of Condensed Matter（Osaka, Japan 23-27.Aug.1999），Collected Abstracts, 224, Aug. 1999
International conference proceedings, English - Temperature dependence of luminescence lifetime in Cu_2_O
N. Harukawa; S. Murakami; S. Tamon; S. Ijuin; A. Ohmori; K. Abe; T. Shigenari
1999 Int. Conf. Luminescence and Optical Spectroscopy of Condensed Matter（Osaka, Japan 23-27.Aug.1999），Collected Abstracts, 174, Aug. 1999
International conference proceedings, English - A NEW INTERPRETATION OF INCOMMENSURATE PHASE IN QUARTZ
T. Shigenari; Y. Makita; M. Yajima; K. Abe; T. A. Aslanyan
9th European Meeting on Ferroelectricity（July 12-16,1999 Praha, Czech）abstracts, 15, Jul. 1999
International conference proceedings, English - Detection of phase relaxation in resonance fluorescence from sodium vapor by a cw mode-locked dye laser
XH Liu; K Tsujino; K Abe; T Shigenari
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 68, 1, 71-76, Jan. 1999, Peer-reviwed, The phase relaxation of the resonance fluorescence from sodium vapor was studied by measuring the contrast of interference between the delayed fluorescence pulses. It is shown that the phase relaxation time can be measured by a conventional cw mode-locked pico-second pulsed laser without any sophisticated apparatus to actively lock the phases of exciting laser pulses. Using a modified Michelson type interferometer, and a homemade software based on FFT algorithm, we obtained a phase correlation time as 300 ps with good S/N ratio. A local minimum observed in the decay curve is attributed to the ground state hyperfine splitting and the temperature dependence of the phase relaxation time is explained by the change in the spread of atomic velocity distribution with temperature (Doppler broadening mechanism). Analytical calculation indicates that when the laser bandwidth is much broader than the linewidth of the fluorescence, as in the present case, the envelope of the interfering fluorescence signal can be represented by Fourier transform of the absorption spectra. The analysis based on this approximation are in good agreement with the results obtained in the experiment.
Scientific journal, English - Fluorescence studies on photo-induced structure changes in purified biphenyl crystals
XH Liu; N Satoh; G Kudo; K Abe; T Shigenari; T Narisawa
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 68, 1, 284-287, Jan. 1999, Peer-reviwed, Fluorescence spectra of pure biphenyl crystals were measured over a wide temperature range. In contrast to the sharp peaks near 530 nm observed in crystals grown from methyl alcohol solution, a new broad band around 500 nm was found in zone-refined crystals at 5.0 K when the intense exciting laser was employed. From the temperature dependent behavior and the fluorescence decay characters, it is suggested that the new excimer-like band is related to photo-induced structural deformation in biphenyl crystals.
Scientific journal, English - Comments on the characteristics of incommensurate modulation in quartz: discussion about a neutron scattering experiment
TA Aslanyan; T Shigenari; K Abe
ACTA CRYSTALLOGRAPHICA SECTION A, MUNKSGAARD INT PUBL LTD, 55, 65-69, Jan. 1999, From analysis of the elastic neutron scattering data of Dolino et al. [J. Phys. (Paris) (1984), 45, 361-371], it is shown that, besides the well identified components u(x) and u(y) of the acoustic displacements in the incommensurate (IC) phase of quartz, there also exists a strong component of the u(z) vector of the modulation. The existence of the large u(z) is not consistent with the currently accepted model for the IC transition in quartz, since the long-period IC modulation observed in quartz cannot induce any noticeable acoustic component u(z). The need for a new model is keenly felt in order to understand the origin of the IC modulation in quartz.
Scientific journal, English - Domain wall solutions for EHM model of crystal
T Shigenari; SV Dmitriev; AA Vasiliev; K Abe
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 68, 1, 117-125, Jan. 1999, Peer-reviwed, For a one-dimensional discrete model of a crystal the solution of the form of a moving domain wall in an odd-periodic commensurate structure was derived in the continuum approximation. The energy of the commensurate odd-periodic structure; the width and the energy of domain wall were expressed in terms of the amplitudes of harmonics of carrying commensurate structure. With the use of the result by Ishibashi, the relation between domain wall solutions in odd-periodic and even-periodic commensurate structures Tvas established. The applicability and the accuracy of the solutions were also discussed. The obtained solutions were found to he more accurate and general than those by other authors.
Scientific journal, English - Dynamics of autowaves in a one-dimensional crystal model
SV Dmitriev; T Shigenari; SM Volkova; AA Vasiliev; K Abe
COMPUTATIONAL MATERIALS SCIENCE, ELSEVIER SCIENCE BV, 13, 4, 227-231, Jan. 1999, Peer-reviwed, A mechanism of the phase transition between two modulated structures with different wave vectors was proposed and investigated numerically. The phase transition occurs through the mechanism of nucleation and growth of the new phase. The role of the nucleus is played by an unstable domain wall and the domain of a new low energy phase grows due to the motion of autowaves. (C) 1999 Published by Elsevier Science B.V. All rights reserved.
Scientific journal, English - Mechanisms of transition between 1q and 2q incommensurate phases in a two-dimensional crystal model
SV Dmitriev; T Shigenari; K Abe
PHYSICAL REVIEW B, AMER PHYSICAL SOC, 58, 5, 2513-2522, Aug. 1998, Peer-reviwed, The two-dimensional elastically hinged molecule model of a crystal which contains two anharmonic terms was studied numerically. The results show that the Iq or 2q incommensurate phase can be stable depending on the parameters of the model. For example, in the sinusoidal incommensurate regime the Iq (2q) phase can be globally stable but in the domain-wall regime the situation can be opposite and the 1q <-> 2q (2q <-> 1q) transition can be expected. Another mechanism of the 1q <-> 2q phase transition stems from the softening of the dispersion surface simultaneously at two points of the Brillouin zone, (kappa(x),0) and (0,kappa(y)) In this case the 2q modulated phase can appear as a linear combination of the two Iq modulated phases. Under the assumption that the dispersion surface is slightly perturbed for some reason, the softening first occurs at one of the two points resulting in the Iq phase formation. Further changing of the external parameters leads to the softening at the second point and the 1q <-> 2q transition can take place. Both these mechanisms of the 1q <-> 2q phase transition were revealed and studied. [S0163-1829(98)07029-5].
Scientific journal, English - Piezoelectric properties in alpha-, incommensurate- and beta-phases of quartz SiO2
T Ochiai; M Ohya; T Nishikawa; Y Sasaki; K Abe; T Shigenari
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, JAPAN J APPLIED PHYSICS, 37, 5A, 2606-2607, May 1998, Peer-reviwed, Piezoelectric properties of quartz SiO2 were obtained using a self-resonance method at 150-200 kHz over a range from room temperature to 960 degrees C, and in detail particularly in the incommensurate phase. Their large elastic anomalies were observed. Piezoelectricity was found to be preserved up to 960 degrees C. The "tridymite phase" was not detected.
Scientific journal, English - Raman scattering in a [ (CH3)(2)NH2](5)Cd3Cl11 crystal
R Sobiestianskas; K Abe; T Shigenari
JOURNAL OF RAMAN SPECTROSCOPY, WILEY-BLACKWELL, 29, 5, 399-404, May 1998, Raman spectra of [ (CH3)(2)NH2](5)Cd3Cl11 (DMAPCC) single crystals were studied over the range 10-3200 cm(-1) between 100 and 360 K. The changes in the external and internal mode region were observed and characterized. In particular, the symmetric stretching vibration of the dimethylammonium (DMA) group at 890 cm(-1) splits continuously over the temperature range 360-110 K. The analysis of the DMA stretching mode based on an order-disorder model showed the presence of competition between long-range interactions in the disordered DMA(3) subsystem and short-range interactions between anions and cations, The change in the wavenumber behaviour of the 893 cm(-1) mode corroborated the presence of a phase transition at 170 K. (C) 1998 John Wiley & Sons, Ltd.
Scientific journal, English - Thermally activated motion of domain wall in a crystal with a small degree of discreteness
SV Dmitriev; T Shigenari; K Abe
COMPUTATIONAL MATERIALS SCIENCE, ELSEVIER SCIENCE BV, 11, 3, 227-232, May 1998, In the frame of the one-dimensional elastically hinged molecule (EHM) model of crystal the thermally activated motion of a rather wide domain wall (DW) was studied by numerical simulation at temperatures much higher than Peierls-Nabarro barrier but much lower than kink-pair nucleation temperature. It was found that DW undergo Brownian-like motion and at some moments the drift velocity of DW can be changed by obtaining (losing) some energy from (to) thermal fluctuations. (C) 1998 Elevier Science B.V. All rights reserved.
Scientific journal, English - On the Origin of the IC Phase in Quartz
T. A. Aslanyan; T. Shigenari; K. Abe
Abstracts The 6-th Japan-CIS/Baltic Symposium on Ferroelectricity（JCBSF-6）, Noda, Japan (March 22-25,1998), 41, Mar. 1998
International conference proceedings, English - Mechanisms of 1q-3q incommensurate phase transition in 2-dimensional crystal model based on hexagonal lattice
S. V. Dmitriev; T. Shigenari; K. Abe
Abstracts The 6-th Japan-CIS/Baltic Symposium on Ferroelectricity（JCBSF-6），Noda, Japan (March 22-25,1998), 42, Mar. 1998
International conference proceedings, English - Fluorescence, studies on structural phase transitions of molecular crystals
XH Liu; N Satoh; G Kudo; K Abe; T Shigenari
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 32, S584-S587, Feb. 1998, Peer-reviwed, Fluorescence spectra and lifetime of biphenyl single crystals were studied over a wide temperature range using a pico-second UV laser. In contrast to the sharp peaks near 530 nm observed in crystals grown from the methyl alcohol solution, a new band around 500 nm was found in zone-refined crystals at 5.0 K when the intense exciting laser was employed. It was found that the lifetime of the intrinsic fluorescence band reaches its minimum at the incommensurate-commensurate structural phase transition point only when the 500 nm broad band appears. The concentration of the accepters is supposed to be increased by the crystal held fluctuations near the phase transition and the lifetime shortening is explained by the Forster transition mechanism.
Scientific journal, English - Debye-Waller factors for incommensurate structures
TA Aslanyan; T Shigenari; K Abe
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 32, S910-S913, Feb. 1998, Peer-reviwed, The Debye-Waller factors exp[-W] for the displacement-type incommensurate (IC) structures are calculated taking into account the correlation of the phases of the modulation. It is shown that W similar to T-i(1/2) /T-Ti/(-1/2) and the IC satellites would not be observed in small vicinities of transitions. A model for the IC transition in quartz is discussed from this point of view.
Scientific journal, English - Ferroelastic properties of the incommensurate phase in quartz
TA Aslanyan; T Shigenari; K Abe; N Ukigaya
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 32, S914-S916, Feb. 1998, Peer-reviwed, It is shown that the incommensurate (IC) phase near the alpha <----> beta transition point in quartz (SiO2) is improper ferroelastic and should be split into domains. The ferroelasticity induces the birefringence for the light propagation along the z-axis, which explains the observed birefringence near T-i (1-k state) and near T-c (3-k state). Acoustic and light scattering anomalies observed in the IC phase are qualitatively consistent with the ferroelastic nature. However, they should be much weaker if the IC structure has a long period modulation, as it is observed in the diffraction experiments. The magnitudes of the observed anomalies can be large only if the IC structure has a short period, not as small as it is observed in quartz. The latter may be considered as a confirmation of the assumption that the long-period IC modulation in quartz is an improper phase and is induced by some other IC structure with a short period.
Scientific journal, English - Computer simulation for the incommensurate phase near the lock-in transition
SV Dmitriev; T Kumata; T Shigenari; K Abe
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 32, S907-S909, Feb. 1998, Peer-reviwed, A phase transition from a high-symmetry to a low-symmetry commensurate phase through an incommensurate (IC) phase was studied in the framework of the one-dimensional elastically hinged molecule model. Emphasis was given to the properties of the domain walls in the IC phase near the lock-in transition.
Scientific journal, English - Debye-Waller factors for incommensurate structures. (共著)
T. A. Aslanyan; T. Shigenari; K. Abe
J. Phys. Condens. Matter., 10, 21, 4565-4576, Jan. 1998, Peer-reviwed
Scientific journal, English - On the origin of the inhomogeneities and birfringence in the incommensurate phase of quartz. (共著)
T. A. Aslanyan; T. Shigenari; K. Abe
J. Phys. Condens. Matter, 10, 21, 4577-4586, Jan. 1998, Peer-reviwed
Scientific journal, English - Some peculiarities in the incommensurate phase transition in quartz
T Shigenari; TA Aslanyan; N Ukigaya; Y Makita; K Abe
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 217, 1-4, 43-51, 1998, Optical anomalies near the phase transition temperature (T-c) from the incommensurate (IC) to the alpha-phase were studied. In particular, large depolarization for a light propagating along the z-axis was found near T-c. The maximum of the birefringence (2.2x10(-5)) were observed in the so-called fog-zone where the 'opalescence' appears. This and the related optical anomalies are due to the ferroelastic strains and domains induced by the modulation. However, the magnitude of the observed birefringence is by far larger than that expected from the currently accepted model unless the IC modulation wavevector k is much larger than that observed in the diffraction experiments. The results suggest the necessity of a new model for the IC phase transition in quartz.
Scientific journal, English - Some peculiarities in the incommensurate phase transition in quartz
T Shigenari; TA Aslanyan; N Ukigaya; Y Makita; K Abe
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 217, 1-4, 43-51, 1998, Peer-reviwed, Optical anomalies near the phase transition temperature (T-c) from the incommensurate (IC) to the alpha-phase were studied. In particular, large depolarization for a light propagating along the z-axis was found near T-c. The maximum of the birefringence (2.2x10(-5)) were observed in the so-called fog-zone where the 'opalescence' appears. This and the related optical anomalies are due to the ferroelastic strains and domains induced by the modulation. However, the magnitude of the observed birefringence is by far larger than that expected from the currently accepted model unless the IC modulation wavevector k is much larger than that observed in the diffraction experiments. The results suggest the necessity of a new model for the IC phase transition in quartz.
Scientific journal, English - On the origin of the in commensurate phase in quartz
TA Aslanyan; T Shigenari; K Abe
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 217, 1-4, 345-353, 1998, Peer-reviwed, The model for the IC transition in quartz is discussed, where the observed long-period IC modulation is interpreted as the third harmonic of the fundamental short-period modulation with the IC vector close to the b/3. (In this model the fundamental modulation is attenuated by the Debye-Waller factor and is not observed in the diffraction experiments). It is shown that the amplitude of the IC third harmonic (particularly its acoustic components) can be larger than that of the fundamental modulation near the lock-in transition to the b/3 phase, and subsequently it is not strongly attenuated by the D-W factor.
Scientific journal, English - Mechanism of transition between 1q and 3q incommensurate phases in two-dimensional crystal model
SV Dmitriev; T Shigenari; K Abe
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 217, 1-4, 179-187, 1998, Peer-reviwed, The one-dimensional elastically hinged molecule (EHM) microscopic model of a crystal was generalised to two dimensions on the base of the hexagonal lattices. The two-dimensional model contains two anharmonic terms which allow, depending on parameters of the model, the stability of Iq, 2q or 3q modulated phase. The phase transition between Iq and 3q IC phases characteristic to the hexagonal system was studied numerically by the molecular dynamics technique. The model shows the sequence of phases as it is in quartz on cooling and explains the increase of the Iq IC phase temperature range in quartz under uniaxial stress.
Scientific journal, English - One-dimensional crystal model for incommensurate phase .2. Compressible molecules
SV Dmitriev; T Shigenari; K Abe
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 66, 9, 2732-2736, Sep. 1997, Peer-reviwed, Influence of the external pressure on the commensurate-incommensurate (IC) phase transition was studied in the frame of the elastically hinged molecule model of crystal which was recently proposed by the present authors. The case of compressible but rather hard molecules was treated.
Scientific journal, English - Effects of proton motions on the fluorescence from 2-naphthol-doped ice Ih and the proton ordering transition
T Akiyama; M Sakamaki; K Abe; T Shigenari
JOURNAL OF PHYSICAL CHEMISTRY B, AMER CHEMICAL SOC, 101, 32, 6205-6207, Aug. 1997, Peer-reviwed, Fluorescence from 2-naphthol-doped ice Ih crystals was studied using a picosecond pulsed laser. Because of the incipient ESPT (excited state proton transfer) process of 2-naphthol in ice, the fluorescence lifetime is sensitive to the change in the proton configurations around the dopant. In addition to the sharp decrease above 120 K due to the increase in the mobility of proton defects, the lifetime shows a dip near 72 K, which is related to the Ih-XI proton ordering transition.
Scientific journal, English - Dynamics of domain walls in an incommensurate phase near the lock-in transition: One-dimensional crystal model
SV Dmitriev; T Shigenari; AA Vasiliev; K Abe
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 55, 13, 8155-8164, Apr. 1997, Peer-reviwed, A phase transition from a high-symmetry to a low-symmetry commensurate phase through an incommensurate phase was studied in the framework of the one-dimensional elastically hinged molecule model which includes only a fourth-order anharmonic potential. The phase diagram with respect to the harmonic-potential coefficient and the external force was obtained. From the numerical analysis of the equation of motion, it was shown that the incommensurate phase near the lock-in transition contains a periodic system of energetically equivalent domain walls which are mutually repulsive. The properties of the domain walls were studied and the lock-in transition was described as the annihilation process of the walls when the repulsion is changed to attraction.
Scientific journal, English - Lineshape of Brillouin spectra in the incommensurate phase of quartz (SiO2): Analysis by Fano's formula
K Abe; K Aboshi; K Kawasaki; T Shigenari
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 203, 1-4, 153-165, 1997, Peer-reviwed, Rayleigh-Brillouin spectra near the a-INC-P phase transition of quartz were measured. Near the INC-phase, a plateau appears between the LA-mode and the Rayleigh line. In order to take account of the interaction between the continuum (two phonon scattering from the soft branch) and the discrete LA-mode, Fano's formula was used in the analysis of the asymmetric spectra. The results are consistent with the interpretation of the low frequency Raman spectra observed by Berge et al. and they also agree with the ultrasonic data indicating that the single relaxation mechanism explains the temperature dependence of the sound wave near the beta --> INC phase transition.
Scientific journal, English - Domain walls in one-dimensional 3-periodic structure
T Shigenari; AA Vasiliev; SV Dmitriev; K Abe
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 203, 1-4, 335-347, 1997, Peer-reviwed, The static and dynamic properties of domain walls in the incommensurate phase near the lock-in transition was studied numerically in the frame of the elastically hinged molecule model of crystal which was recently proposed by the present authors. The case of discommensurations in the 3-periodic commensurate phase was discussed and the analytical expression for the displacements near the domain wall was derived in continum approximation. The interaction of the domain pattern with the external field, processes of collision and breakup of domain walls were investigated.
Scientific journal, English - One-dimensional crystal model for incommensurate phase .1. Small displacement limit
SV Dmitriev; K Abe; T Shigenari
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 65, 12, 3938-3944, Dec. 1996, Peer-reviwed, A simple one-dimensional crystal model was proposed in order to study the incommensurate phase formation and its properties were numerically analyzed. In this model each particle (molecule) of the crystal has two degrees of freedom so that a longitudinal sound wave propagation is possible. In the case of small displacements and incompressible molecules the model has the Hamiltonian identical to that for a linear chain with a local fourth order anharmonic potential and the harmonic nearest- and next-nearest-neighbor interactions. Particular emphasis has been placed on the analysis of the incommensurate phases caused by the soft modes with short wavelength which has not been studied in most of the previous investigations.
Scientific journal, English - Fluorescence spectra of photo-induced impurity and phase transitions in a biphenyl crystal
XH Liu; N Satoh; K Abe; T Narisawa; T Shigenari
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 29, S751-S755, Nov. 1996, Peer-reviwed, Fluorescence spectra of biphenyl single crystals grown from methyl-alcohol solution were studied over a wide temperature range by the 295nm UV laser. A fluorescence band near 530nm which is far below the intrinsic emission band. In spite of the fact that it originates from photo-chemically produced impurities, some of the fine structures of the band correspond to the low frequency lattice vibrations of the host crystal and the temperature dependence of the bending motion of the phenyl rings at 186cm(-1) reflects the orderness of the incommensurate phase transitions of the host crystal at 40K and 17K. The results are compared with the intrinsic fluorescence from the purified crystals.
Scientific journal, English - Studies on fluctuations in strongly first-order phase transitions by fluorescence
T Shigenari; K Abe; T Akiyama; T Takeuchi; K Morita
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, KOREAN PHYSICAL SOC, 29, S764-S768, Nov. 1996, Peer-reviwed, In case of strongly first-order phase transitions, in which large displacements of the molecules are involved, the lifetime of the fluorescence excited by a pico-second laser was found to decrease sharply on approaching the transition temperature T-0. The lifetime shortening is attributed to the fluctuation increase towards the stability Limits of the low temperature phase.
Scientific journal, English - Line shape of the Raman spectrum and the disorder mechanism of the methylammonium group in a [ (CH3)(2)NH2]5Cd3Cl11 crystal
R Sobiestianskas; K Abe; T Shigenari
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 65, 10, 3146-3149, Oct. 1996, Peer-reviwed, The Raman line shape of the symmetric stretching vibration of the dimethylammonium (DMA) group at 890 cm(-1) in the spectrum for a [ (CH3)(2)NH2]5Cd3Cl11 (DMAPCC) crystal was analyzed. The temperature dependence of this vibration mode is explained in terms of the motional narrowing due to the disordered NH2 group in DMA(3), which results in splitting of the DMA(2) line in the internal mode region. The disorder mechanism is discussed by comparing the results with the two relaxation times obtained from the dielectric dispersion data.
Scientific journal, English - Laser-induced Fluorescence Spectra and Phase Transitions in Bipheny Crystals
X.Liu; N.Satoh; K.Abe; T.Shigenari
J. Phys. Soc. Jpn, 65, 3801-3806, Jul. 1996, Peer-reviwed
Scientific journal, English - A study of proton dynamics in ice using an excited state proton transfer (ESPT) of a dopant molecule and its fluorescence
T Akiyama; K Okazaki; Q Ping; K Abe; T Shigenari
PHYSICA B-CONDENSED MATTER, ELSEVIER SCIENCE BV, 219-20, 574-576, Apr. 1996, Peer-reviwed, It is shown that the fluorescence lifetime from 2-naphthol-doped ice can be utilized as a sensitive probe of the proton dynamics in ice. The possibility of the detection of the proton-ordering transition at 72 K in 2-naphthol-doped ice by this method is demonstrated.
Scientific journal, English - Acoustic phonon dispersion of SiO2 (quartz) near the incommensurate phase transition
S Ishibashi; K Abe; M Suzuki; Y Sasaki; T Shigenari
PHYSICA B-CONDENSED MATTER, ELSEVIER SCIENCE BV, 219-20, 593-595, Apr. 1996, Peer-reviwed, Acoustic phonons in quartz were studied by Brillouin, ultrasonic and piezoelectric resonance methods. The dispersion of LA phonons in the incommensurate (INC) phase can be interpreted by a single relaxation mechanism. A TA phonon (c(66)) shows a small anomaly at the INC transition temperature and it critically changes near the lock-in transition from INC to alpha-phase. The fluctuation effects of the soft TA-Sigma branch phonon on the sound velocity were found to be much less than those in other crystals.
Scientific journal, English - FLUORESCENCE-SPECTRA AND LIFETIME OF 2-NAPHTHOL IN H2O-ICE(I-H) AND D2O-ICE(I-H) SINGLE-CRYSTAL
Q PING; K OKAZAKI; T AKIYAMA; K ABE; T SHIGENARI
SOLID STATE COMMUNICATIONS, PERGAMON-ELSEVIER SCIENCE LTD, 95, 3, 177-180, Jul. 1995, Peer-reviwed, Proton dynamics were studied by a new fluorescence method using a cw-mode locked picosecond laser. Fluorescence spectra of 2-naphthol(2-NpOH) doped in single crystals of ice I-h (H2O and D2O) were measured from about 10K to 300K. In H2O ice, a broad band emission and six sharp bands were found in the near UV (340 similar to 385nm) range, while in D2O ice, besides avery weak broad band, only three sharp bands were observed. The broad band emission can be assigned to a neutral 2-NpOH interacting with a large number of water molecules and the sharp bands are considered to be due to an isolated cluster of 2-NpOH with a small number of water molecules. The less structured spectra in D2O ice and the lifetime difference between H2O and D2O ice are consistent with the fact that the rate of excited state proton transfer (ESPT) is retarded by deuteration. One of the sharp bands at 370nm was found to be peculiar since its lifetime (similar to 0.2ns at T<40K) is much shorter than that of the broad band (similar to 5.2ns). The behaviour suggests that it is determined by the so-called intrinsic ESPT time.
Scientific journal, English - ACOUSTIC-PHONON DISPERSION IN THE INCOMMENSURATE PHASE OF SIO2 (QUARTZ)
E TANAKA; S ISHIBASHI; K ABE; M SUZUKI; T SHIGENARI
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 64, 1, 136-141, Jan. 1995, Peer-reviwed, Ultrasonic and Brillouin scattering measurements were performed near the incommensurate (INC) transition of SiO2 (quartz). The decrease of the LA sound velocity in the INC phase was found to be much less for 10 MHz than for 27 GHz, being remarkably different from other crystals which undergo INC phase transitions. The dispersion in the INC phase can be well characterized by a simple Landau-Khalatnikov type relaxation with a relaxation time tau(T) = (2.6 +/- 0.5) x 10(-12) (T-i - T)(-1) s. A small but critical decrease of the TA velocity as T --> T-c(= T-i - 1.4 K) was also detected by the ultrasonic measurement.
Scientific journal, English - Lifetime of the impurity-induced fluorescence and zero-phonon line emission in a biphenyl crystal
Keishin Shinjo; Kiyoshi Morita; Kohji Abe; Takeshi Shigenari
Ferroelectrics, 168, 1, 223-230, 1995, Peer-reviwed, Fluorescence spectrum and its lifetime in a biphenyl single crystal were measured by a picosecond UV laser pulse. It was found that in addition to an impurity induced broad band fluorescence, a zero-phonon line appears at 533 nm if the excitation energy is larger than the band gap energy, in a single crystal of biphenyl. In contrast to a temperature insensitive lifetime of the zero-phonon emission, the broad band fluorescence was shown to have a shortest lifetime at T1 reflecting the divergence of the fluctuation of atomic displacement near the phase transition at 40 K. © 1995, Taylor &
Francis Group, LLC. All rights reserved.
Scientific journal, English - TEMPERATURE-DEPENDENCE OF FLUORESCENCE LIFETIME OF 2-NAPHTHOL IN ICE (I-H) CRYSTAL - A STUDY OF THE PROTON MOTION IN ICE
P QI; K OKAZAKI; T AKIYAMA; K ABE; T SHIGENARI
CHEMICAL PHYSICS LETTERS, ELSEVIER SCIENCE BV, 230, 4-5, 322-328, Dec. 1994, Peer-reviwed, The lifetime of the fluorescence from 2-naphthol (C10H8OH) doped in ice I-h was measured from 27 to 300 K. The slow component tau(s) (5.3 ns at 27 K) shows a significant decrease in the temperature range 130-200 K, while the faster component (tau f approximate to 0.7 ns) shows a slight decrease above 200 K. The relative intensity I-f/I-s increases above 130 K. The results were interpreted in terms of a model involving the transfer between the two states, S-1 and S-1 which correspond to the excited states of 2-naphthol with and without considering the trapping of proton with L defects in ice, respectively.
Scientific journal, English - PRECURSOR OF A STRONG 1ST-ORDER PHASE-TRANSITION - CRITICAL SPEEDING-UP OF FLUORESCENCE LIFETIME IN THE ALPHA-BETA-TRANSITION OF RESORCINOL
T SHIGENARI; K ABE; K MORITA; Q PING; E KOJIMA; H INO
JOURNAL OF PHYSICS-CONDENSED MATTER, IOP PUBLISHING LTD, 6, 36, 7469-7482, Sep. 1994, Peer-reviwed, A precursor of a strong first-order structural phase transition has been detected as the critical speeding-up of the lifetime of the fluorescence excited by a picosecond pulsed laser. In the alpha-beta transition of a resorcinol (C6H4(OH)2) crystal, a critical decrease of the lifetimes and an increase in the intensity of the impurity-induced fluorescence were found from about 30 K below T(c). This is in contrast with the fact that the temperature dependence of the Raman spectra and the dielectric constant shows no precursor effect. From a detailed polarization study, large-amplitude and short-lived vibrational fluctuations associated with the phase transition are suggested as a possible origin of the precursor. Despite the apparent contradiction of the fluctuation-dissipation theorem, the results indicate that divergence of the fluctuation also takes place in the first-order phase transition. The method provides a new approach to the study of a first-order phase transition.
Scientific journal, English - MACROSCOPIC SYMMETRY OF THE INCOMMENSURATE PHASE OF QUARTZ
K. Abe; A. Kakuho; T. Shigenari; Y. Sasaki; Y. Takeuchi
FERROELECTRICS, TAYLOR & FRANCIS LTD, 155, 347-352, 1994, Peer-reviwed, It is shown group-theoretically that the symmetry of macroscopic properties in INC phase of quartz could be either C-6, C-2 or D-2 depending on the state of INC phase. IR spectra in the INC phase were measured and the increase of damping was observed, but so far no experimental evidence of the predicted symmetry was obtained from the IR and Raman spectra.
Scientific journal, English - Precursor of a Melting Transtion : Fluorescence and Light Scattering Studies of a sucrose crystal
K.Morita; K.Shinjo; Qi Ping; K.Abe; T.Shigenari
Ferroelectrics, 159, 203-208, 1994, Peer-reviwed
Scientific journal, English - Effect of Fluctuations on the Fluorescence Lifetime in Strong First Order Transitions
T.Shigenari; K.Abe; K.Morita; Qi Ping; E.Kojima
Ferroelectrics, 159, 209-214, 1994, Peer-reviwed
Scientific journal, English - SYNCHROTRON AND LIGHT-SCATTERING OBSERVATION OF THE 1Q INCOMMENSURATE PHASE OF QUARTZ UNDER ZERO-STRESS
SOULA, V; K ABE; P BASTIE; G DOLINO; B CAPELLE; YL ZHENG
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 48, 10, 6871-6879, Sep. 1993, Peer-reviwed, We present evidence for the existence of a 1q incommensurate phase at zero stress in quartz, in a temperature interval of about 0.05 K, between the high-temperature beta phase and the usual 3q incommensurate phase. White-beam synchrotron-radiation topography gives a direct picture of the three possible orthorhombic 1q domains. The coexistence of the two phases at the first-order 1q-3q transition has also been observed. Further information was obtained by light-scattering experiments, giving a peak of the scattered light intensity at the beta-1q transition, and a step increase of the intensity at the 1q-3q transition, and by light-depolarization measurements. These results on the observation of the zero-stress 1q phase are discussed in relation with predictions from mean-field theory and from considerations of fluctuation and impurity effects.
Scientific journal, English - OPTICAL STUDY OF TIME-VARIATION OF MEMORY EFFECT IN INCOMMENSURATE PHASE OF QUARTZ
K ABE; G DOLINO
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 62, 4, 1101-1104, Apr. 1993, Peer-reviwed, New observations of the memory effect in the incommensurate phase of quartz have been performed with birefringence measurements. The enhancement and the decay of the memory effect have been measured for various writing times. A linear relationship between the decay time and the writing time has been found, which cannot be explained by the usual diffusion model of the memory effect. We also present the first observation of a memory effect in a light scattering experiment.
Scientific journal, English - EVIDENCE OF FOLDED ACOUSTIC PHONON MODES IN THE LIGHT-SCATTERING SPECTRUM OF INCOMMENSURATE QUARTZ
M VALLADE; K ABE; B BERGE; T SHIGENARI
JOURNAL OF PHYSICS-CONDENSED MATTER, IOP PUBLISHING LTD, 4, 49, 9931-9938, Dec. 1992, Peer-reviwed, Low-frequency light scattering spectra of the incommensurate phase of quartz show the presence of weak additional peaks in the 6-12 cm-1 range. These peaks are shown to correspond to 'folded' acoustic phonons with a wavevector close to the incommensurate modulation wavevector. A transverse acoustic mode and a longitudinal mode can be identified in the (ZZ) and (X + Y, Z) polarization configurations, respectively. Selection rules for Raman activation of acoustic modes are derived in the special case of the 'triple-q' incommensurate structure, and the results are compared with experimental observations.
Scientific journal, English - THERMAL-DIFFUSIVITY AND SURFACE-TENSION OF LIQUID-NITROGEN NEAR ITS CRITICAL-POINT
T SHIGENARI; M MOGI; K ABE; M SUZUKI; N ITAGAKI; A SATO
SLOW DYNAMICS IN CONDENSED MATTER, AIP PRESS, 256, 475-476, 1992, Peer-reviwed
International conference proceedings, English - Critical Speeding-up of the Fluorescence Lifetime near the Structural Phase Transition
T.Shigenari; K.Abe; Y.Ino; K.Morita; E.Kojima
Springer. Proc. in Phys.68, 282, 1992, Peer-reviwed
International conference proceedings, English - DETECTION OF A PRECURSOR IN A STRONG 1ST-ORDER STRUCTURAL PHASE-TRANSITION BY A FLUORESCENCE-LIFETIME MEASUREMENT
T SHIGENARI; E KOJIMA; Y INO; K ABE
PHYSICAL REVIEW LETTERS, AMERICAN PHYSICAL SOC, 66, 16, 2112-2115, Apr. 1991, Peer-reviwed, A precursor of the strong first-order structural phase transition in a resorcinol [C6H6(OH)2] crystal was detected by measuring the lifetime of the fluorescence. A critical decrease in the lifetime and an increase in the intensity of the impurity-induced fluorescence were found to occur starting from 30 K below T(c). Large-amplitude and short-lived vibrational fluctuations associated with the phase transition are suggested as a possible origin of the precursor.
Scientific journal, English - Effect on Uniaxial Stress on Central Peaks in the 1q and 3q Incommensurate Phase of Quarty
Abe Kohji; Kawasaki Kenji; Kowada Kazuteru; Shigenari Takeshi
J. Phys. Soc. Jpn., The Physical Society of Japan (JPS), 60, 2, 60-407, 1991, The effects of uniaxial stress $\sigma_{yy}$ on the incommensurate (INC) phase transition of quartz have been investigated by light scattering spectroscopy. The 1q INC phase is induced between $\beta$ and the 3q INC phase and its region becomes wider with the increase of stress. Anomalies of the central peak in the Rayleigh-Brillouin spectra are observed at three temperatures, corresponding to $T_{i1}$ ($\beta$ to 1q INC phase), $T_{i3}$ (1q to 3q INC phase) and $T_{\text{c } }$ (3q to $\alpha$ phase). Only at $T_{i1}$, is the central peak found to have a dynamical component.
English - DYNAMICAL CENTRAL PEAK NEAR THE INCOMMENSURATE PHASE-TRANSITION OF QUARTZ
K ABE; K KAWASAKI; T KOIKE; T SHIGENARI
JOURNAL OF PHYSICS-CONDENSED MATTER, IOP PUBLISHING LTD, 1, 44, 8741-8746, Nov. 1989, Peer-reviwed
Scientific journal, English - OPTICAL HETERODYNED COHERENT BRILLOUIN SPECTROSCOPY (OHD-BIKES) USING CONTINUOUS-WAVE (CW) DYE-LASERS
T HAGA; M HIGUCHI; K ABE; T SHIGENARI
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, JAPAN J APPLIED PHYSICS, 28, 7, 1199-1205, Jul. 1989, Peer-reviwed
Scientific journal, English - OPTICAL OBSERVATION AND LIGHT-SCATTERING STUDIES ON THE INCOMMENSURATE PHASE IN QUARTZ
T SHIGENARI; K ABE
FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 95, 253-257, 1989, Peer-reviwed
Scientific journal, English - LIGHT-SCATTERING FROM E-SYMMETRY AMPLITUDON IN THE INCOMMENSURATE PHASE OF QUARTZ
T SHIGENARI; K ABE; T SHIONOYA; T HAGA; M SUGIYAMA
SOLID STATE COMMUNICATIONS, PERGAMON-ELSEVIER SCIENCE LTD, 64, 3, 367-370, Oct. 1987, Peer-reviwed
Scientific journal, English - Opticla and X-ray Studies of Domain Formation in KH2PO4 Crystal
Kohji Abe
J. Phys. Soc. Jpn, 56, 2, 785-809, 1987, Peer-reviwed
Scientific journal, English - TEMPERATURE-DEPENDENT LOW-FREQUENCY MODES IN THE INCOMMENSURATE PHASE OF QUARTZ
T SHIONOYA; K ABE; T SHIGENARI
JOURNAL OF PHYSICS C-SOLID STATE PHYSICS, IOP PUBLISHING LTD, 19, 23, 4547-4560, Aug. 1986, Peer-reviwed
Scientific journal, English - FERROELECTRIC DOMAIN FORMATION IN SHORT CIRCUITED KH2PO4
E NAKAMURA; S USHIO; K ABE
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 53, 1, 403-407, 1984, Peer-reviwed
Scientific journal, English - QUASI-ONE-DIMENSIONAL BEHAVIOR OF THERMAL-EXPANSION IN FERROELECTRIC CSH2PO4
E NAKAMURA; K ABE; K DEGUCHI
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOCIETY JAPAN, 53, 5, 1614-1616, 1984, Peer-reviwed
Scientific journal, English - THE ANOMALOUS BEHAVIOR OF THE COERCIVE FIELD IN LOSSY KH2PO4
K ABE; E NAKAMURA; S USHIO
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOCIETY JAPAN, 53, 9, 3220-3226, 1984, Peer-reviwed
Scientific journal, English - DILATOMETRIC STUDY OF THE PHASE-TRANSITION OF QUASI-ONE-DIMENSIONAL FERROELECTRIC CSH2PO4
K DEGUCHI; E OKAUE; S USHIO; E NAKAMURA; K ABE
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOCIETY JAPAN, 53, 9, 3074-3080, 1984, Peer-reviwed
Scientific journal, English - ANOMALOUS BEHAVIOR OF SPONTANEOUS STRAIN IN FERROELECTRIC CESIUM DIHYDROGEN PHOSPHATE, CSH2PO4
K DEGUCHI; E OKAUE; K ABE; E NAKAMURA
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOCIETY JAPAN, 50, 9, 2783-2784, 1981, Peer-reviwed
Scientific journal, English - Dielectric properties of lossy KH2PO4 crystals
Eiji Nakamura; Kazuyuki Itoh; Satoshi Ushio; Kohji Abe; Hirohisa Yoshida
Japanese Journal of Applied Physics, 20, 59-62, 1981, Peer-reviwed, Single crystals of KH2PO4 have been prepared from aqueous solutions which contain a large amount of KOH. These crystals have high dielectric constants and dielectric losses at room temperature and show dielectric dispersion below about 105 Hz. The dispersion frequency increases with the increase of the amount of KOH in the aqueous solution. In the ferroelectric phase, these crystals exhibit low dielectric constants and show anomalous frequency dependence of the coercive field. © 1981 The Japan Society of Applied Physics.
Scientific journal, English
MISC
- Raman Spectra in Ferroelectric SrTi^18^O_3_
Kohji Abe; Keiji Yamashita Yoshiharu Tomita; Takeshi Shigenari Ruiping Wang; Mitsuru Itoh
2002, Ferroelectrics, 272, 155-160 - 水晶(SiO2)の低波数光散乱スペクトルー不整合相とα-β相転移-
重成武; 阿部浩二
アグネ技術センタ-, 1987, 固体物理, 22, 6, 6-423, Japanese, Introduction other, 0454-4544, 40001388323, AN00092629
Lectures, oral presentations, etc.
- Temperature Dependence of Specific Heat in SnxSr1-xTiO3(x=0.02,0.05,0.10)
Y. Kogai; H. Tanaka; K. Abe; T. Nakano
Poster presentation, Japanese, 日本物理学会 2018 年秋季大会 概要集, 日本物理学会, 同志社大学, Domestic conference
10 Sep. 2018 - Raman Spectroscopy of La1-xSrxFeO3
前田晴信; 鈴木智絢; 佐藤恒太郎; 中野諭人; 阿部浩二
Poster presentation, Japanese, 日本物理学会講演概要集, Domestic conference
23 Mar. 2018 - 単結晶LaFeO3のラマン散乱スペクトル
前田晴信; 鈴木智絢; 佐藤恒太郎; 中野諭人A; 阿部浩二
Poster presentation, Japanese, 日本物理学会 2017 年秋季大会 概要集, Domestic conference
23 Sep. 2017 - SnxSr1-xTO3のラマン散乱スペクトルⅢ
中野諭人; 長谷川敦司; 阿部浩二
Poster presentation, Japanese, 日本物理学会第72回年次大会（2017）, 日本物理学会, 大阪府豊中市 大阪大学豊中キャンパス, Domestic conference
18 Mar. 2017 - Introducing of CPL Method to Basic Physics Workshop in UEC
Jin Nakamura; Masaru Suzuki; Naruo Sasaki; Yuki Fuseya; Nobuhito Kokubo; Tohru Takada; Kohji Abe
Oral presentation, Japanese, 日本物理学会 第 71 回年次大会（2016 年）講演概要集, 日本物理学会, 宮城県仙台, Domestic conference
19 Mar. 2016 - 強誘電体SnドープSrTiO3のRaman散乱スペクトルの温度変化
中野諭人; 三上 悠; 阿部浩二; 鈴木祥一郎; 秋山健二; 安藤陽
Oral presentation, Japanese, 日本物理学会 第70回年次大会 講演概要集, Domestic conference
21 Mar. 2015 - 電通大「チーム教育（共有教育）」でのグループ学習Ⅱ
阿部浩二; 金長正彦; 小久保伸人; 鈴木勝; 高田亨; 中村仁; 伏屋雄紀
Oral presentation, Japanese, 日本物理学会 第70回年次大会 講演概要集, Domestic conference
21 Mar. 2015 - 電気通信大学における「パスポートプログラム」の取り組みIII
赤石暁; 阿部浩二; 石田尚行; 岡田佳子; 奥野剛史; 清水崇文; 白川英樹; 鈴木勝; 高田亨; 中村淳; 中村仁; 細見斉子; 山北佳宏
Oral presentation, Japanese, 日本物理学会2014年秋季大会概要集, Domestic conference
08 Sep. 2014 - 電通大「チーム教育（共有教育）」でのグループ学習
阿部浩二; 金長正彦; 小久保伸人; 鈴木勝; 高田亨; 中村仁; 伏屋雄紀
Oral presentation, Japanese, 日本物理学会2014年秋季大会, Domestic conference
07 Sep. 2014 - 『電通大における新しい物理学演習の試み
中村仁; 伏屋雄紀; 小久保伸人; 佐々木成朗; 高田亨; 鈴木勝; 阿部浩二
Oral presentation, Japanese, 日本物理学会2014年秋季大会, Domestic conference
07 Sep. 2014 - La2-xCaxCoO4の電荷秩序近傍のラマンスペクトル
前原彪 佑; 角田嘉人; 中野諭人; 阿部浩二; 堀金和正
Poster presentation, Japanese, 日本物理学会講演概要集第69巻, Domestic conference
Sep. 2014 - 強誘電体SnドープSrTiO3のラマンスペクトル
中野諭人; 三上 悠; 阿部浩二; 鈴木祥一郎; 秋山健二; 安藤陽
Oral presentation, Japanese, 第３１回強誘電体応用会議予稿集, 京都, Domestic conference
May 2014 - 電通大「チーム教育（共通教育）」教育対象の変遷と教育結果
阿部浩二; 金長正彦; 小久保伸人; 鈴木勝; 高田亨; 中村仁; 伏屋雄紀
Oral presentation, Japanese, ，日本物理学会第69回年次大会, Domestic conference
27 Mar. 2014 - 電気通信大学における「パスポートプログラム」の取り組みII
細見斉子; 赤石暁; 阿部浩二; 石田尚行; 岡田佳子; 奥野剛史; 白川英樹; 鈴木勝; 高田亨; 中村淳; 中村仁; 山北佳宏
Oral presentation, Japanese, 日本物理学会2013年秋季大会, Domestic conference
27 Sep. 2013 - 電通大「チーム教育（共通教育）」eラーニングでの電磁気概念理解度
阿部浩二; 金長正彦; 小久保伸人; 鈴木勝; 高田亨; 中村仁; 伏屋雄紀
Oral presentation, Japanese, 日本物理学会2013年秋季大会, Domestic conference
27 Sep. 2013 - 強誘電体SnドープSrTiO_3のRaman散乱スペクトルの温度変化
三上 悠; 中野諭人; 阿部浩二; 鈴木祥一郎; 秋山健二; 安藤陽
Oral presentation, Japanese, 日本物理学会 2013年秋季大会講演概要集, Domestic conference
26 Sep. 2013 - Managing the learning quality in physics by e-learning improvement with collaboration education
M. Kanenaga; M.Suzuki; K. Abe; J. Nakamura; T. Takada; N. Kokubo; Y. Fuseya
Oral presentation, English, APPC12, International conference
16 Jul. 2013 - 電通大「チーム教育（共有教育）」で実施した電磁気学基礎概念調査
阿部浩二; 金長正彦; 鈴木勝; 高田亨; 中村仁
Oral presentation, Japanese, 日本物理学会概要集,日本物理学会第68回年次大会
Mar. 2013 - Selective excitation and detection of coherent phonon with dual-frequency injection locked pulse
T. Nakano; T. Morita; T. Sato; D. Matsumoto; K. Abe; M. Katsuragawa
Oral presentation, Japanese, Japanese Society of Applied Physics
Mar. 2013 - Temperature dependence of Raman Spectra of La_2-x_Ca_x_CoO_4_ III
Y. Kakuta; T. Nakano; K. Abe; K. Horigane
Oral presentation, Japanese, 日本物理学会概要集,日本物理学会 第68回年次大会
Mar. 2013 - Shape estimation of needle nanoparticles by light scattering
M. Yoshiki; T. Nakano; K. Abe; S. Sato; T. Yonezawa; A. Hasegawa
Oral presentation, Japanese, 日本物理学会概要集,日本物理学会 第６８回年次大会
Mar. 2013 - ：Raman spectra of C_60_ intercalated graphite
R. Umehara; M. Oka; T. Nakano; K. Abe; M. Suzuki
Oral presentation, Japanese, 日本物理学会概要集,日本物理学会 第６８回年次大会
Mar. 2013 - 任意二周波数注入同期レーザーによるコヒーレントフォノンの選択的高効率励起
中野諭人; 森田宇亮; 佐藤智信; 阿部浩二; 桂川真幸
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会2012秋季大会
Sep. 2012 - La_2-x_Ca_x_CoO_4_のラマンスペクトルの温度変化Ⅱ
角田嘉人; 中野諭人; 阿部浩二; 堀金和正
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会2012秋季大会
Sep. 2012 - 電通大「チーム教育（共有教育）」でのe-ラーニング改善とその効果
阿部浩二; 金長正彦; 鈴木勝; 高田亨; 中村仁
Oral presentation, Japanese, 日本物理学会2012秋季大会
Sep. 2012 - 2周波数注入同期レーザーによる音響フォノン高密度励起と検出
中野諭人; 児玉雄太; 森田宇亨; 阿部浩二; 桂川眞幸
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会第67回年次大会
Mar. 2012 - La_2-x_Ca_x_CoO_4_ のラマン散乱スペクトルの温度変化
角田嘉人; 掛谷泰隆; 松川恩; 中野諭人; 阿部浩二; 堀金和正
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会第67回年次大会
Mar. 2012 - 電通大「チーム教育（共有教育）」の実施結果と追跡調査
阿部浩二; 金長正彦; 葛東方; 鈴木勝; 高田亨; 中村仁
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会第67回年次大会
Mar. 2012 - 任意に周波数注入同期レーザーによるGHz-THzビートパルスの生成
中野諭人; 森田宇亮; 佐野光彦; 阿部浩二; 桂川真之
Oral presentation, Japanese, 応用物理学会,第72回学術講演会
Sep. 2011 - SrTi^18^O_3_(STO18)の不均一強誘電的ドメイン形成と光学特性
中野諭人; 山本周太郎; 野間拓司; 橘陽一郎; 酒井喜英; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会第66回秋季大会
Sep. 2011 - 任意二周波数注入同期レーザーを用いた水晶のコヒーレント音響フォノン励起
中野諭人; 佐野光彦; 阿部浩二; 桂川眞幸
Oral presentation, Japanese, 日本物理学会講演概要集,第66回日本物理学会
Mar. 2011 - 任意二波長注入同期パルスによる音響フォノン励起
中野諭人; 小泉健太; 佐野光彦; 児玉雄太; 森田宇亮; 阿部浩二; 桂川眞幸
Oral presentation, Japanese, レーザー学会,レーザー学会学術講演会第31回年次大会
Jan. 2011 - 「コア・カリキュラム学習支援」システムの改善手法
浅井吉蔵; 阿部浩二; 大槻一雅; 大淵泰司; 奥野剛史; 尾関之康; 金長正彦; 島田宏; 清水和子; 鈴木勝; 中村仁; 本山美穂; 渡辺信一
Oral presentation, Japanese, 日本物理学会概要集,日本物理学会６５回年次大会
Mar. 2010 - 選択的二波長発振注入同期レーザーによる光コヒーレンス音波生成
中野諭人; 小泉健太; 佐野光彦; 阿部浩二; 桂川眞幸
Oral presentation, Japanese, 日本物理学会６５回年次大会
Mar. 2010 - Polarized dependency of Raman spectra and infrared absorption of La_<2-x>Co_xCoO_4
O. matsukawa; T. Nakano; K. Horigane; T. Kobayashi; M. Suzuki; K. Abe
Oral presentation, Japanese, Meeting abstracts of the Physical Society of Japan
Sep. 2009 - 二波長注入同期レーザーの開発
小泉健太; 中野諭人; 小野瀬貴士; 阿部浩二; 桂川眞幸
Oral presentation, Japanese, 応用物理学会
Sep. 2009 - イットリウム鉄ガーネットの誘電緩和と磁気緩和の試料依存性
新井伸英; 榎下峻平; 小林義彦; 阿部浩二; 中村仁; 浅井吉蔵
Oral presentation, Japanese, 日本物理学会講演概要集
Sep. 2009 - 水晶(SiO2)の不整合相転移点近傍での分域形成過程
柏愉美子; 寺田大亮; 中野諭人; 阿部浩二; 水野薫; 岡本博之
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会台６４回年次大会
Mar. 2009 - 酸素同位体置換したSrTiO3（STO18）の強誘電的分域による透過光強度の温度塩化
山本周太郎; 野間拓志; 橘陽一郎; 中野諭人; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会概要集,日本物理学会
Mar. 2009 - コヒーレントフォノン励起に向けた二波長発振注入同期パルスレーザーの開発
中野諭人; 小泉健太; 小野瀬貴士; 阿部浩二; 桂川眞幸
Oral presentation, Japanese, 日本物理学会概要集,２００９年秋季大会
Mar. 2009 - Study support based on Students Karte for the core curriculum
浅井吉蔵; 阿部浩二; 大槻一雅; 大淵泰司; 奥野剛史; 尾関之康; 金長正彦; 島田宏; 清水和子; 鈴木勝; 中川徹夫; 中村仁; 渡辺信一
Oral presentation, Japanese, 日本物理学会講演概要集,日本物理学会第６４回年会
Mar. 2009 - 層状コバルト酸化物La_2-xCa_xCoO_4の超音波測定
堀金和正; 小林利章; 鈴木勝; 阿部浩二; 浅井吉蔵; 秋光純
Oral presentation, Japanese, 日本物理学会,第６３回年秋季大会
Sep. 2008 - 酸素同位体置換したSrTiO3（STO18)の光学的特性：透過率の温度変化
山本周太郎; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会,第６３回年次大会
Mar. 2008 - 同位体置換したSrTiO3（STO18)のソフトモードと強誘電相での不均一性
阿部浩二; 山本周太郎; 重成 武
Oral presentation, Japanese, 日本物理学会,第６３回年次大会
Mar. 2008 - X線トポグラフによる水晶のINC相相転移近傍の変調構造及び分域構造の観察
柏愉美子; 阿部浩二; 重成武; 水野薫; 岡本博之
Oral presentation, Japanese, 日本物理学会,第６２回年次大会
Sep. 2007 - ボロンドープダイヤモンドのラマンスペクトル及び赤外吸収スペクトルII
佐藤貴之; 兼田紗衣; 中村仁; 阿部浩二; 山田修義; 竹之内智大; 入山慎吾; 川原田洋; 長尾雅則; 高野義彦
Oral presentation, Japanese, 日本物理学会,第62回年次大会
Sep. 2007 - SrTi18O3の高周波領域におけるラマン散乱スペクトル
酒井喜秀; 赤池 崇; 市川正和; 阿部浩二; 重成 武; 伊藤 満; 王端平
Oral presentation, Japanese, 日本物理学会講演概要集,第６１回日本物理学会
Sep. 2006 - ボロンドープダイヤモンドのラマンスペクトル及び赤外吸収スペクトル
大石 亮; 佐藤貴之; 中村 仁; 阿部浩二; 山田修義; 栄長泰明; 川原田洋; 竹ノ内智大; 高野義彦; 長尾雅則
Oral presentation, Japanese, 日本物理学会講演概要集,第６１回日本物理学会
Sep. 2006 - KOHドープ氷単結晶のXI相でのラマンスペクトル：波数ベクトルの方向依存性
大竹佑也; 富澤広樹; 阿部浩二
Oral presentation, Japanese, 日本物理学会,第６１回年次大会
Mar. 2006 - ボロンドープダイヤモンドのラマン及びX線吸収分光
大石亮; 佐藤貴之; 中村仁; 阿部浩二; 山田修義; 栄長泰明; 川原田洋; 竹ノ内智大; 高野義彦; 長尾雅則
Oral presentation, Japanese, 日本物理学会,第６１回年次大会
Mar. 2006 - 酸素同位体置換SrTiO3のラマン散乱と光学測定
赤池崇; 酒井秀喜; 重成武; 阿部浩二; 伊藤満; 王端平
Oral presentation, Japanese, 日本物理学会,２００５年秋期大会
Sep. 2005 - 水晶のα-INC相転移点近傍でのX線回折、
大池芳徳; 豊永元寛; 阿部浩二; 重成武; 池田直; 水牧仁一朗
Oral presentation, Japanese, 日本物理学会,日本物理学会第６０回年次大会
Mar. 2005 - ICE-XI相のラマン散乱：libration mode の同定
三浅崇生; 大竹佑也; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会,第６０回年次大会
Mar. 2005 - 液晶5CB、8CBの相転移と蛍光スペクトルの温度変化
阿部浩二; 宇佐美敦司; 石田憲士; 大石亮; 重成武
Oral presentation, Japanese, 日本物理学会,２００４年秋季大会
Sep. 2004 - MD計算によるSiO2(水晶）の相転移I：0Kでの変調構造
重成武; D.セマギン; S.V.セルゲイ; 阿部浩二
Oral presentation, Japanese, 日本物理学会,２００４年秋季大会
Sep. 2004 - MD計算によるSiO2(水晶）の相転移II：高温での変調構造
D.セマギン; 重成武; S.V.セルゲイ; 阿部浩二
Oral presentation, Japanese, 日本物理学会,２００４年秋季大会
Sep. 2004 - STO18の電場印可ラマンスペクトル
竹本智彦; 佐中敦; 赤池崇; 阿部浩二; 重成武; 伊藤満; 王端平
Oral presentation, Japanese, 日本物理学会,第５９回年次大会
Mar. 2004 - 氷のプロトン秩序化相転移の赤外ラマンスペクトル
中野浩二; 山本浩史; 長田睦; 三浅崇生; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会講演概要集
Mar. 2003 - SrTiO3(STO18)のドメインとラマンスペクトル
阿部浩二; 竹本智彦; 佐中敦; 重成武; 伊藤満
Oral presentation, Japanese, 日本物理学会講演概要集
Mar. 2003 - 液晶（5CB）の相転移と蛍光
石田憲士; 宇佐美敦司; 岡本庄司; 福島義治; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会講演概要集
Mar. 2003 - SiO2（水晶）のTA分枝のソフト化と不整合相転移
長嶺守洋; 阿部浩二; S.V.Dmitriev; D.Semagin; 重成武
Oral presentation, Japanese, 日本物理学会講演概要集
Sep. 2002 - SiO2（水晶）の相転移のMDシミュレーション：３倍周期構造の安定性
D.Semagin; 長嶺守洋; 功刀政和; 阿部浩二; 重成武; S.V.Dmitriev
Oral presentation, Japanese, 日本物理学会講演概要集
Sep. 2002 - 氷のプロトン秩序化相転移の赤外・ラマンスペクトル：電場効果
中野浩二; 山本浩史; 中島理樹; 阿部浩二; 重成武
Oral presentation, Japanese, 日本物理学会講演概要集
Sep. 2002 - HoNi_2_B_2_Cの超音波測定(4)
末武美樹; 高橋洋子; 鈴木勝; 石田進; 竹屋浩幸; 黒木和彦; 阿部浩二
Oral presentation, Japanese, 日本物理学会講演概要集
Mar. 2002 - Intrinsic localized modes as a precursor of the first order phase transition.
ドミトリエフ セルゲイ; 重成武; 阿部浩二
Oral presentation, Japanese, 日本物理学会講演概要集
Mar. 2002 - 同位体置換SrTiO3(STO18)のラマンスペクトルⅢ
阿部浩二; 山下啓司; 竹本智彦; 丸本祥太郎; 重成武; 王端平; 伊藤満
Oral presentation, Japanese, 日本物理学会講演概要集57
Mar. 2002 - HoNi_2_B_2_Cの超音波研究(3)
高橋洋子; 末武美樹; 鈴木勝; 石田進; 竹屋浩幸; 黒木和彦; 阿部浩二
Oral presentation, Japanese, 日本物理学会,徳島,2001.9.17-20
Sep. 2001 - SrTiO３18（STO18）のラマンスペクトル
山下啓司; 阿部 浩二; 重成武; 王端平; 伊藤満
Oral presentation, Japanese, 日本物理学会講演概要集
Sep. 2001 - 回転の自由度を持つ系の弾性的性質
S.V.ドミトリエフ; 重成武; 阿部 浩二; 石橋善弘
Oral presentation, Japanese, 日本物理学会講演概要集
Sep. 2001 - Biphenyl結晶の相転移と蛍光スペクトル
水野正樹; 石田憲士; 福島義治; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会第56回年次会(3月27日-3月30日,日本物理学会第56回年次会(3月27日-3月30日)，
Mar. 2001 - SrTiO_3_（STO18）のラマンスペクトル
山下敬司; 冨田良治; 阿部浩二; 重成 武; 王 瑞平; 伊藤 満
Oral presentation, Japanese, 日本物理学会,日本物理学会第56回年次会(3月27日-3月30日)，
Mar. 2001 - MD simulation of Modulated Structures in Quartz
S. V. Dmitriev; D. A. Semagin; 矢島美樹; 長嶺守洋; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会第56回年次会
Mar. 2001 - ゆらぎのプローブとしての電子励起状態
阿部浩二; 重成武
Public symposium, Japanese, 「新ソフトモード概念の構築」, 北海道大学電子技術研究所, 札幌
Jan. 2001 - SiO_2_(水晶)の分散関係とラマンスペクトル
矢島美樹; 長嶺守洋; S. V. ドミトリエフ; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会第55回(9月22日-25日)，
Sep. 2000 - p-terphenylの結晶の吸収・蛍光と相転移（Ⅱ）
福島義治; 鈴木利洋; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会第55回(9月22日-25日)，
Sep. 2000 - 氷のIh─XIプロトン秩序化相転移のラマン散乱
阿部浩二; 中嶋理樹; 重成 武
Public symposium, Japanese, 「水素結合誘電体―水素結合プロトンの振動スペクトルと同位体効果」研究会, 高エネルギー加速器研究機構
Mar. 2000 - 氷XI相のラマンスペクトル（Ⅲ）
中嶋理樹; 山本浩史; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会2000年春の分科会（関西大学），
Mar. 2000 - SiO_2_（水晶）のMD計算（Ⅱ）
S.ドミトリエフ; 矢島美樹; 牧田佳也; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会2000年春の分科会（関西大学）
Mar. 2000 - SiO_2_水晶）の不整合相でのラマンスペクトルと光学観察
牧田佳也; 矢島美樹; 和地 功; S.ドミトリエフ; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会講演概要集(3/22-9/25),日本物理学会2000年春の分科会（関西大学）
Mar. 2000 - Cu_2_Oの銅欠陥発光の温度特性とその解析
春川宗永; 村上貞俊; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会1999年秋の分科会
Sep. 1999 - 離散系のSine-Gordon方程式での３ソリトンブリーザの寿命
S. ドミトリエフ; 宮内 健; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会1999年秋の分科会
Sep. 1999 - GPI（[NH_4_CH_2_COO]H_2_PO_4_）の相転移とRaman散乱
阿部浩二; 王 蘭義; R. Sobiestianskas; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会第５４回1999年秋の分科会
Sep. 1999 - フェムト秒時間分解分光によるα水晶のEモード２
佐藤公宣; 吉岡伸也; 辻見裕史; 重成 武; 阿部浩二; 八木駿郎
Oral presentation, Japanese, 日本物理学会,日本物理学会第54回年次大会
Mar. 1999 - Biphenyl結晶の蛍光及び吸収と構造相転移
工藤源一郎; 今井孝志; 水野正樹; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会第54回年会
Feb. 1999 - MD計算による水晶の圧力誘起不整合相転移
セルゲイ・ドミトリエフ; 矢島美樹; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会第54回年会
Feb. 1999 - 氷XI相のラマンスペクトル
石井一正; 中嶋理樹; 福田秀之; 阿部浩二; 重成 武
Oral presentation, Japanese, 日本物理学会,日本物理学会1998年秋の分科会
Sep. 1998 - 弱い摂動下のsine-Goldon方程式におけるソリトンの強い非弾性衝突
S. V. Dmitriev; 阿部浩二; 重成 武; A. A. Vasilliev; A. E. Miroshnichenko
Oral presentation, Japanese, 日本物理学会,日本物理学会1998年秋の分科会
Sep. 1998 - フェムト秒時間分解分光によるα水晶のEモード
佐藤公宣; 吉岡伸也; 辻見裕史; 重成 武; 阿部浩二; 八木駿郎
Oral presentation, Japanese, 日本物理学会,日本物理学会1998年秋の分科会
Sep. 1998 - 変位型不整合相転移での衛星反射のDebye-Waller因子
重成 武; 阿部浩二; T. Aslanyan
Oral presentation, Japanese, 日本物理学会,日本物理学会1998年秋の分科会
Sep. 1998
Courses
Research Themes
- 新規誘電体材料Snドープチタン酸ストロンチウムの強誘電性発現のメカニズム
阿部 浩二
Principal investigator
2016 - 2018 - 顕微ラマン散乱分光によるSn,PbドープSrTiO3の 誘電応答とドープされた原子の役割の解明
中野諭人
公益財団法人村田学術振興財団, 研究助成
Jul. 2014 - Aug. 2015 - Origin of Incommensurate Phase Transition and the New Viewpoint on the Phase Fluctuation
SHIGENARI Takeshi; DMITRIEV Sergey v.; ABE Kohji
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), The aim of this project is to show that the effect of phase fluctuation plays the crucial role in appearance of incommensurate structure in crystals. We propose a new model to explain the origin of the incommensurate phase transition in quartz. In this model, the intensity of the satellite intensity observed in diffraction experiments is strongly attenuated due to the decrease of Debye-Waller factor, which is attributed to the phase fluctuation. In this research we have proved this model from the following method. (1) From the detailed investigation of low frequency Raman spectrum in the high symmetry beta phase, the temperature dependence of the integrated intensity was found not to exactly follow the Curie-Weiss law ,but deviates from 30K above the incommensurate phase transition temperature. This is consistent with our model. (2) The MD calculation was performed using Tsuneyuki potential. The result shows that the short period modulation is more likely to appear than long wave modulation in contrast to the currently accepted model. (3) The characteristics of incommensurate structure in' dielectric crystals are explained by the rotational degree of freedom of certain group of atoms. The elastically hinged molecule (EHM) model was proposed. The dynamics of the transition is investigated by the computer simulation using the EHM model. The negative poison ratio and several non-linear soliton-like behavior of lattice were also investigated by this and similar models., 11640311
1999 - 2001 - Electronic Properties of Singvle-Crystal Oxide Films Fabricated on Metal Surfaces
MURATA Yoshitada; ABE Koji; YAMADA Chikashi; SHIGENARI Takeshi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), High-quality single-crystal films of α-Al_2O_3 9A thick and SiO_2 30 A thick have been fabricated on metal surfaces of Ru(0001) and Ni(111), respectively. α-Al_2O_3 was fabricated by a phase transition from γ- to α-Al_]2O_3 having a commensurate structure with Ru(0001). Atomic hydrogen during initial growth of an amorphous SiO_2 film and ambient oxygen atmosphere during annealing of this film were essential in forming the single-crystal SiO_2 film on Ni(111). An extraordinary result that the band gap for the oxide layer decreases with decreasing oxide thickness was preliminarily observed using scanning tunneling spectroscopy (STS). This result was confirmed by medium-resolution electron energy loss spectroscopy, in. which the oxide thickness V. dependence of the band gap was measured by α-Al_2O_3 films with various oxide thicknesses below 35 A. For growing ultra-thin films of transition metals on a single-crystal oxide, i.e. a wide band gap crystal, we have, utilized the band gap narrowing and succeeded in making a monoatomic layer (ML) of a Pt film on α-Al_2O_3(9 A)/Ru(0001). We have investigated electronic properties of the oxide layer using C-O vibrational frequencies of CO adsorbed on Pt(1 ML)/α-Al_2O_3(9 A)/Ru(0001) measured by reflection absorption infrared spectroscopy. On the other hand, the crystal structure of SiO_2 film thick 40 A was investigated by grazing incidence X-ray diffraction using syncrotron radiation. A nice single crystal film of β-quartz is fabricated with a thickness of 30 A and a polycrystalline Ni silicide film 10 A thick is formed with a mosaic structure at the interface. These single-crystal oxide films on metal surfaces are new surface materials, which will open a window against other fields of solid state physics and chemistry., 11440090
1999 - 2000 - Studies on the proton dynamics and melting of ice crystals
SHIGENARI Takeshi; ABE Kohji
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Univ.Electro-Communications, Grant-in-Aid for Scientific Research (C), In this study, we have established a new fluorescence method which can be used for the study of proton dynamics in ice crystals. 2-naphthol molecule was chosen ad the fluorescence probe to be excited by a pico-second pulse laser. The following results were obtained. (1) The decay curves of the fluorescence after the pulsed excitation were well explained by the ESPT (excited state proton transfer) model. (2) A stepwise decrease in the flurescence lifetime from 5ns to 2ns was observed near 120K,which is consistent with the increase in the mobility of the proton in ice above 120K.They were both attributable to the L-defect mobility increase. (3) The lifetime shortening as well as the increase of the intensity ratio between the fast and slow components were observed around 72K.This temperature is identified as the proton ordering transition, which have been observed only in KOH-dopedice in dielectric and calorimetric measurements. The precent result shows that our fluorescence mothod has high sensitivity to detect the local tendency of proton ordering near the probe naphthol moleculesince the fluctuation increase near the transition makes the excited state of the probe molecule less stable and makes the lifetime short. We conclude that the inclusion of the probe molecule would locally break the so-called ice rule and stimulate the proton ordering eve without KOH-doping. (4) In order to see how the naphthol molecule is included in ice crystal, we grew a pure naphthol crystal by a vacuum sublimation method. From the comparison of the naphthol-doped ice spectra, we have assigned the vibrational structure in the fluorescence spectra. The result shows that there is a characteristic zero phonon shift depending on the type of inclusion, which will be useful for the continuing study on the melting transition of ice. These results were partly published in several journals and also presented in the International Meeting on the Physics an Chemistry of Ice held in New Hampshire in Aug.1996. (Proc.will be soon published in J.Phys.Chem.), 07640438
1995 - 1996 - Studies on the precursor phenomena and the relaxation processes of melting transitions of crystals by a fluorescence
SHIGENARI Takeshi; ABE Kohji; TAKEUCHI Yoshio; SASAKI Yukihiko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, THE UNIVERSITY OF ELECTRO-COMMUNUCATIONS, Grant-in-Aid for General Scientific Research (C), Using a newly developed method for the studies on the dynamic of phase transitions, the following results were obtained. (1).A molecular crystal 'Sucrose' was investigated with a pico-second pulsed laser. It was found the lifetime of the fluorescence sharply decreases as the melting point is approached. By comparing with the X-ray study, it was found that the onset of the observed shortening from a temparature about 25K below Tm was an indication of the collapsing process of the regular crystal structure into an amorphous state. This would be the first measurement of a precursor of a melting transition by light. (2) A single crystal of ice(Ih) doped with 2-naphthol(2-C8H10(0H)) molecules was grown. The fluorescence lifetime measurements recealed that a stepwise decrease of lifetime from 5ns to 2ns occurs between 130K and 200K.The behavior was analyzed by a model which takes into account the relaxation of the proton configurations in the neighborhood of the naphthol molecules. The analysis allowed us to estimate the activation energy for the generation of L-defects in ice. (3) A structural phase transition of a single crystal biphenyl was investigated by a similar method. The lifetime shows a minimum at the transition temperature Tc=40K, where biphenyl undergoes a second order incommensurate phase transition. In conrast to the significant change in the lifetime of the broadband fluorescence, a sharp zero-phono line at lambda=533nm was found to have a rather long lifetime without any critical temperature depenedence. All the results confirmed that that the present method can be a sensitive probe of fluctuations associated with the phase transitions and would be able to be applied to variety of phase transitions. The results were reported, e.g.in the 8th International Meeting on Ferroelectricity and will appear in several journal(in press and submitted)., 04640329
1992 - 1993
