阿部 浩二

学長・理事等(役員)学長特別補佐
名誉教授・その他関係者名誉教授

学位

  • 理学修士, 広島大学大学院
  • 理学博士, 広島大学
  • Doctor of Science, The University of Hiroshima

研究キーワード

  • Dielectrics
  • Ferroelectrics
  • Solidsstate physics
  • structural phase transition
  • Light sacttering spectroscopy
  • 誘電体
  • 固体物性
  • 構造相転移
  • 光散乱分光

研究分野

  • 自然科学一般, 半導体、光物性、原子物理

経歴

  • 2007年04月 - 2022年03月
    電気通信大学, 教授
  • 1996年04月 - 2007年03月
    電気通信大学, 助教授
  • 1994年04月 - 1996年03月
    電気通信大学, 講師
  • 1987年12月 - 1994年03月
    電気通信大学, 助手
  • 1985年09月 - 1987年12月
    電気通信大学, 文部技官教務職

学歴

  • 1985年08月
    広島大学, 理学研究科, 物性学専攻
  • 1982年03月
    広島大学, 理学研究科, 物性学専攻
  • 1980年03月
    広島大学, 理学部, 物性学科
  • 1976年03月
    愛媛県立八幡浜高等学校

委員歴

  • 2015年04月 - 2017年03月
    日本物理学会代議員, 日本物理学会, 学協会
  • 2015年04月 - 2016年03月
    日本物理学会領域10代表, 日本物理学会
  • 2014年04月 - 2015年03月
    日本物理学会領域10領域副代表, 日本物理学会, 学協会
  • 2002年 - 2003年
    editor of the jounal of the physical society of Japan, 学協会
  • 2002年 - 2003年
    日本物理学会ジャーナル編集委員, 日本物理学会, 学協会
  • 1999年 - 1999年
    フォノン物性分科世話人, 日本物理学会, 学協会
  • 1998年 - 1998年
    誘電体文科世話人, 日本物理学会, 学協会

受賞

  • 受賞日 2012年05月
    epljournal IOP publishing
    2011年優秀論文賞(EPL:欧州物理)
    グレートブリテン・北アイルランド連合王国(英国)

論文

  • 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巻, 掲載ページ 111-120, 出版日 2019年02月11日, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 017018-1-017018-4, 出版日 2014年09月, 査読付
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 1号, 掲載ページ 72-79, 出版日 2014年05月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 18-23, 出版日 2014年04月01日, 査読付
    研究論文(学術雑誌), 英語
  • Vibrational modes of hydrogens in the proton ordered phase XI of ice:Raman spectra above 400 cm−1
    Takeshi Shigenari; Kohji Abe
    THE JOURNAL OF CHEMICAL PHYSICS, AMER INST PHYSICS, 136巻, 17号, 掲載ページ 174504, 出版日 2012年05月, 査読付, 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]
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 1-11, 出版日 2012年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 67-74, 出版日 2012年, 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).
    研究論文(学術雑誌), 英語
  • Observation of Domain Structures Near the α-INC-β 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巻, 1号, 掲載ページ 3-8, 出版日 2012年, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 5号, 掲載ページ 57001-1-57001-5, 出版日 2011年06月, 査読付, 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
    研究論文(学術雑誌), 英語
  • 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,, 掲載ページ 397-401, 出版日 2011年05月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 57001, 出版日 2011年05月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 10号, 掲載ページ 104506-1-11, 出版日 2011年03月, 査読付, 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]
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 66-71, 出版日 2011年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 58-65, 出版日 2011年, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 25号, 掲載ページ 26409-26416, 出版日 2010年12月, 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
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 54-57, 出版日 2010年03月, 査読付
    研究論文(学術雑誌), 日本語
  • 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巻, 掲載ページ 204-207, 出版日 2010年, 査読付, 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.
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 掲載ページ 130-+, 出版日 2010年, 査読付, 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.
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 掲載ページ 17-24, 出版日 2010年, 査読付
    研究論文(大学,研究機関等紀要), 日本語
  • 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巻, 1-2号, 掲載ページ 59-66, 出版日 2009年, 査読付, 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.
    研究論文(大学,研究機関等紀要), 日本語
  • Significant softening of C66 and hidden order parameter in the magnetic ordered state of La_(2-x)Ca_xCoO_4 ( 0.4 ≤ x ≤ 0.7)
    K. Horigane; T. Kobayashi; M. Suzuki; K. Abe; K. Asai; J. Akimitsu
    Physical Review B,, AMER PHYSICAL SOC, 78巻, 14号, 掲載ページ 144108-1,-6, 出版日 2008年10月, 査読付, 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).
    研究論文(学術雑誌), 英語
  • Photoluminescence properties of Eu3+-doped ZnO nanoneedles
    Katsuyuki Ebisawa; Tsuyoshi Okuno; Kohji Abe
    JAPANESE JOURNAL OF APPLIED PHYSICS, JAPAN SOC APPLIED PHYSICS, 47巻, 9号, 掲載ページ 7236-7238, 出版日 2008年09月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 8号, 掲載ページ 084701.1-084701.8, 出版日 2008年08月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Origin of the Ferroelectricity in SrTi18O3 Studied by Raman Scattering
    Takeshi Shigenari; Kohji Abe
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 369巻, 掲載ページ 117-126, 出版日 2008年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 138-147, 出版日 2008年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Raman scattering study of proton ordered ice-XI single crystal
    K. Abe; Y. Ootake; T. Shigenari
    PHYSICS AND CHEMISTRY OF ICE, ROYAL SOC CHEMISTRY, 掲載ページ 101-108, 出版日 2007年, 査読付
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 掲載ページ 012002, 出版日 2007年, 査読付, 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.
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 掲載ページ 101-108, 出版日 2007年, 査読付
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 17号, 掲載ページ 174121, 出版日 2006年11月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Character of the incommensurate modulation and the problem of light scattering in quartz near the αーβ transition
    T.A.Aslanyan; T.Shigenari; K.Abe; D.A.Semagin
    Phys.Rev.B, AMERICAN PHYSICAL SOC, 73巻, 15号, 掲載ページ 153101, 出版日 2006年04月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 17号, 出版日 2006年, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 220-223, 出版日 2005年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 300-302, 出版日 2005年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 224-227, 出版日 2005年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 11号, 掲載ページ 3057-3060, 出版日 2004年, 査読付, 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.
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 5号, 掲載ページ 052101, 出版日 2003年08月, 査読付, 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)].
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 141-147, 出版日 2003年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 415-422, 出版日 2003年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ S30-S33, 出版日 2003年, 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.
    研究論文(学術雑誌), 英語
  • Strong first order phase transitions studied by Raman and fluorescence spectroscopy
    T Shigenari; K Abe
    RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY, INTERPERIODICA, 77巻, 掲載ページ S40-S46, 出版日 2003年, 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.
    研究論文(学術雑誌), 英語
  • Raman spectra in ferroelectric (SrTiO3)-O-18
    K Abe; K Yamashita; Y Tomita; T Shigenari; RP Wang; M Itoh
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 272巻, 掲載ページ 2147-2152, 出版日 2002年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Elastically hinged molecule model: Discrete medium and continuum
    SV Dmitriev; H Jimbo; K Abe; T Shigenari
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 267巻, 掲載ページ 361-366, 出版日 2002年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • MD calculation for modulated phase in quartz
    DA Semagin; SV Dmitriev; K Abe; T Shigenari; T Aslanyan
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 268巻, 掲載ページ 227-232, 出版日 2002年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • On the light scattering in some crystals with triple-period commensurate phases
    TA Aslanyan; T Shigenari; K Abe
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 272巻, 掲載ページ 2097-2103, 出版日 2002年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Raman spectra in ferroelectric (SrTiO3)-O-18
    K Abe; K Yamashita; Y Tomita; T Shigenari; RP Wang; M Itoh
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 272巻, 掲載ページ 2147-2152, 出版日 2002年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 2153-2158, 出版日 2002年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Elastically Hinged Molecule Model: Relation Between Discrete Media and Continuum
    S.V. Dmitoriev; H.Jimbo; K. Abe; T.Shigenari
    Abstrct, 掲載ページ 32, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 230, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • MD calculation for Modulated Phase in Quartz
    D.A.Semagin; S. V. Dmitriev; K.Abe; T.Shigenari; T.A.Aslanyan
    Abstract, 掲載ページ 63, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 156, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • Raman Spectra of GPI(Glycine Phosphite) single Crystal.
    K.Abe,L.Y.Wang; R.Sobiestianskas; K.Yamashita; T.Shigenari
    Abstract, 掲載ページ 171, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 171, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • On the Light Scattring in Some Crystals with Triple-Period Commensurate.
    T.A.Aslanyan; T.Shigenari; K.Abe
    Abstract, 掲載ページ 176, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • Raman Spectra in Ferroelectric SrTi18O3: Effect of Electric Field.
    K.Abe; K.Yamashita; Y.Tomita; T.Shigenari; R.Wang; M.Itoh
    Abstract, 掲載ページ 179, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • Excited State as a Probe of Structural Phase Transitions in PolyPhenyl Crystals.
    T.Shigenari; K.Abe; M.Mizuno; T.Suzuki; T.Narisawa
    Abstract, 掲載ページ 179, 出版日 2001年09月
    研究論文(国際会議プロシーディングス), 英語
  • Periodic metastable structures in the discrete φ4 model
    S.V. Dmitriev; H.Jimbo; K. Abe; T.Shigenari
    Phys.Rev. E,, 64巻, 掲載ページ 036202-1, 出版日 2001年08月
    研究論文(学術雑誌), 英語
  • 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巻, 5号, 掲載ページ 1431-1432, 出版日 2001年05月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 2号, 掲載ページ 428-436, 出版日 2001年02月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1-4号, 掲載ページ 103-108, 出版日 2001年, 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.
    研究論文(学術雑誌), 英語
  • Elastically hinged molecule model in physics of ferroelectric materials
    SV Dmitriev; DA Semagin; K Abe; AA Vasiliev; T Shigenari
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 262巻, 1-4号, 掲載ページ 1027-1032, 出版日 2001年, 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.
    研究論文(学術雑誌), 英語
  • Elastically Hinged Molecule Model: Rrelation between discreet Media and Continuum
    S.V.Dmitriev; N.Jinbo; K.Abe; T.Shigenari
    Abstract, 掲載ページ 3-7, 出版日 2001年
    研究論文(国際会議プロシーディングス), 英語
  • Elastically hinged molecule model in physics of ferroelectric materials
    SV Dmitriev; DA Semagin; K Abe; AA Vasiliev; T Shigenari
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 262巻, 1-4号, 掲載ページ 1027-1032, 出版日 2001年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1-4号, 掲載ページ 103-108, 出版日 2001年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1-2号, 掲載ページ 122-134, 出版日 2000年12月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 3-4号, 掲載ページ 303-307, 出版日 2000年09月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 1231-1233, 出版日 2000年05月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 1237-1239, 出版日 2000年05月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 623-625, 出版日 2000年05月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 444-446, 出版日 2000年05月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Kink-breather solution in the weakly discrete Frenkel-Kontrova model(共著)
    S. V. Dmitriev; T. Miyauchi; K. Abe; T. Shigenari
    Phys. Rev. E, AMERICAN PHYSICAL SOC, 61巻, 5号, 掲載ページ 5880-5885, 出版日 2000年05月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 2号, 掲載ページ 113-117, 出版日 2000年02月, 査読付, 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.
    研究論文(学術雑誌), 日本語
  • 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巻, 1-4号, 掲載ページ 321-328, 出版日 2000年, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 623-625, 出版日 2000年, 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.
    研究論文(学術雑誌), 英語
  • 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号, 掲載ページ 243-244, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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号, 掲載ページ 574-575, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1-4号, 掲載ページ 321-328, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1-4号, 掲載ページ 871-878, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 138号, 掲載ページ 243-244, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 138号, 掲載ページ 574-575, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1-4号, 掲載ページ 1413-1420, 出版日 2000年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 2号, 掲載ページ 113-117, 出版日 2000年
    日本語
  • 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巻, 掲載ページ S1392-S1395, 出版日 1999年11月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 41号, 掲載ページ 8175-8176, 出版日 1999年10月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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, 掲載ページ 176, 出版日 1999年08月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 122, 出版日 1999年08月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 224, 出版日 1999年08月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 174, 出版日 1999年08月
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 15, 出版日 1999年07月
    研究論文(国際会議プロシーディングス), 英語
  • Detection of Phase Relaxation in Resonance Fluorescence from Sodium Vapor by a cw Mode-Locked Dye Laser(共著)
    X. Liu; K. Tsujino; K. Abe; T. Shigenari
    J. Phys. Soc. Jpn, PHYSICAL SOC JAPAN, 68巻, 1号, 掲載ページ 71-76, 出版日 1999年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Fluorescence Studies on Photo-induced Structure changes in Purified Biphenyl Crystals(共著)
    X. Liu; N. Satoh; G. Kubo; K. Abe; T. Shigenari; T. Narisawa
    J. Phys. Soc. Jpn., PHYSICAL SOC JAPAN, 68巻, 1号, 掲載ページ 284-287, 出版日 1999年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Comments on the characteristics of the incommensurate modulation in quartz. discussion about a neutron scattering experiment(共著)
    T. A. Aslanyan; T. Shigenari; K. Abe
    Acta Cryst., MUNKSGAARD INT PUBL LTD, 55巻, 掲載ページ 65-69, 出版日 1999年01月, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 117-125, 出版日 1999年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Dynamics of Auto-waves in a One-Dimensional Crystal Model(共著)
    S. V. Dmitriev; T. Shigenari; S. M. Volkova; A. A. Vasiliev; K. Abe
    Computatinal Materials Science, ELSEVIER SCIENCE BV, 13巻, 4号, 掲載ページ 227-231, 出版日 1999年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Mechanisms of transition between 1q and 3q incommensurate phases in a two-dimensional crystal model. (共著)
    S. V. Dmitriev; T. Shigenari; K. Abe
    Phys. Rev. B, AMER PHYSICAL SOC, 58巻, 5号, 掲載ページ 2513-2522, 出版日 1998年08月, 査読付, 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].
    研究論文(学術雑誌), 英語
  • Piezoelectric Properties in α-, Incommensurate- and β-Phases of Quartz SiO2. (共著)
    T. Ochiai; M. Ohya; T. Nishikawa; Y. Sasaki; K. Abe; T. Shigenari
    Jpn. J. Appl. Phys, JAPAN J APPLIED PHYSICS, 37巻, 5A号, 掲載ページ 2606-2607, 出版日 1998年05月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Raman Scattering in a [ (CH3)2NH2]5Cd3Cl11 Crystal. (共著)
    R. Sobiestianskas; K. Abe; T. Shigenari
    J. Raman Spectroscopy 29, WILEY-BLACKWELL, 29巻, 5号, 掲載ページ 399-404, 出版日 1998年05月, 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.
    研究論文(学術雑誌), 英語
  • Thermally activated motion of domain wall in a cryatal with a small degree of discreteness. (共著)
    S. V. Dmitriev; T. Shigenari; K. Abe
    Comp. Materials Science 11, ELSEVIER SCIENCE BV, 11巻, 3号, 掲載ページ 227-232, 出版日 1998年05月, 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.
    研究論文(学術雑誌), 英語
  • 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), 掲載ページ 41, 出版日 1998年03月
    研究論文(国際会議プロシーディングス), 英語
  • 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), 掲載ページ 42, 出版日 1998年03月
    研究論文(国際会議プロシーディングス), 英語
  • Fluorescence Studies on Structural Phase Transitions of Molecular Crystal. (共著)
    X. Liu; N. Satoh; G. Kudo; K. Abe; T. Narisawa; T. Shigenari
    J. Korean Phys. Soc., KOREAN PHYSICAL SOC, 32巻, 掲載ページ S584-S587, 出版日 1998年02月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Debye-Waller factors for incommensurate structures. (共著)
    T. A. Aslanyan; T. Shigenari; K. Abe
    J. Korean Phys. Soc., KOREAN PHYSICAL SOC, 32巻, 掲載ページ S910-S913, 出版日 1998年02月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Ferroelastic Properties of the Incommmensurate Phasae in Quartz. (共著)
    T. A. Aslanyan; T. Shigenari; K. Abe; N. Ukigaya
    J. Korean Phys. Soc., KOREAN PHYSICAL SOC, 32巻, 掲載ページ S914-S916, 出版日 1998年02月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Computer Simulation for the Incommensurate Phase near the Lock-in Transition. (共著)
    S. V. Dmitriev; T. Kumata; T. Shigenari; K. Abe
    J. Korean Phys. Soc., KOREAN PHYSICAL SOC, 32巻, 掲載ページ S907-S909, 出版日 1998年02月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Debye-Waller factors for incommensurate structures. (共著)
    T. A. Aslanyan; T. Shigenari; K. Abe
    J. Phys. Condens. Matter., 10巻, 21号, 掲載ページ 4565-4576, 出版日 1998年01月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 21号, 掲載ページ 4577-4586, 出版日 1998年01月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 1-4号, 掲載ページ 43-51, 出版日 1998年, 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.
    研究論文(学術雑誌), 英語
  • Some Peculiarities in the Incommensurate Phase Transition in Quartz(共著)
    T. Shigenari; T. Aslanyan; N. Ukigaya; Y. Makita; K. Abe
    Ferroelectrics, GORDON BREACH SCI PUBL LTD, 217巻, 1-4号, 掲載ページ 43-51, 出版日 1998年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • On the Origin of the Incommensurate Phase in Quartz(共著)
    T. A. Aslanyan; T. Shigenari; K. Abe
    Ferroelectrics, GORDON BREACH SCI PUBL LTD, 217巻, 1-4号, 掲載ページ 345-353, 出版日 1998年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Mechanism of transition between 1q and 3q incommensurate phases in two-dimensional crystal model(共著)
    S. V. Dmitriev; T. Shigenari; K. Abe
    Ferroelectrics, GORDON BREACH SCI PUBL LTD, 217巻, 1-4号, 掲載ページ 179-187, 出版日 1998年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • One-Dimensional Crystal Model for Incommensurate Phase. II. Compressible Molecules. (共著)
    S.V.Dmitriev; T.Shigenari; K.Abe
    J. Phys. Soc. Jpn, PHYSICAL SOC JAPAN, 66巻, 9号, 掲載ページ 2732-2736, 出版日 1997年09月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Effect of Proton Motions on the Fluorescence from 2-Naphthol-Dopted Ice In and the Proton Ordering Transition. (共著)
    T.Akiyama; M.Sakamaki; K.Abe; T.Shigenari
    J. Phys. Chem., AMER CHEMICAL SOC, 101巻, 32号, 掲載ページ 6205-6207, 出版日 1997年08月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Dynamics of domain walls in an incommensurate phase near the Lock-in transition : One-dimensional crystal model(共著)
    S.V.Dmitriev; T. Shigenari; A.A.Vasiliev; K.Abe
    Physical Review B, AMERICAN PHYSICAL SOC, 55巻, 13号, 掲載ページ 8155-8164, 出版日 1997年04月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Lineshape of Brillouin Spectra in the Incommensurate Phase of Quartz(SiO2) : Analysis by Fano's Formula, (共著)
    K.Abe; K.Aboshi; K.Kawasaki; T.Shigenari
    Ferroelectrics, GORDON BREACH SCI PUBL LTD, 203巻, 1-4号, 掲載ページ 153-165, 出版日 1997年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Domaim Walls in One-Dimensional 3-Periodic Structure. (共著)
    T.Shigenari; A.A.Vasiliev; S.V.Dmitriev; K.Abe
    Ferroelectrics, GORDON BREACH SCI PUBL LTD, 203巻, 1-4号, 掲載ページ 335-347, 出版日 1997年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 12号, 掲載ページ 3938-3944, 出版日 1996年12月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Fluorescence Spectra of Photo-induced Impurity and Phase Transitions in a Biphenyl Crystal(共著)
    Xiao-hong Liu; N.Satoh; K.Abe; T.Narisawa; T.Shigenari
    Journal of the Korean Physical Society, KOREAN PHYSICAL SOC, 29巻, 掲載ページ S751-S755, 出版日 1996年11月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ S764-S768, 出版日 1996年11月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Line Shape of the Raman Spectrum and the Disorder Mechanism of the Methylammonium Group in a[ (CH3)2NH2]5Cd3Cl11 Crystal(共著)
    R.Sobiestianskas; K.Abe; T.Shigenari
    Journal of the Physical Society of Japan. (J. Phys. Soc. Jpn), PHYSICAL SOC JAPAN, 65巻, 10号, 掲載ページ 3146-3149, 出版日 1996年10月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Laser-induced Fluorescence Spectra and Phase Transitions in Bipheny Crystals
    X.Liu; N.Satoh; K.Abe; T.Shigenari
    J. Phys. Soc. Jpn, 65巻, 掲載ページ 3801-3806, 出版日 1996年07月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 574-576, 出版日 1996年04月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 593-595, 出版日 1996年04月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 3号, 掲載ページ 177-180, 出版日 1995年07月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 136-141, 出版日 1995年01月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 1号, 掲載ページ 223-230, 出版日 1995年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 4-5号, 掲載ページ 322-328, 出版日 1994年12月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • Precursor of Strong First Order Phase Transition : Critical Speeding-up of Fluorescence lifetime in the α-β Transition of Resorcinol.
    T.Shigenari; K.Abe; K.Morita; Qi Ping; E.Kojima; Y.Ino
    J. Phys. : Condens. Matter, IOP PUBLISHING LTD, 6巻, 36号, 掲載ページ 7469-7482, 出版日 1994年09月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • MACROSCOPIC SYMMETRY OF THE INCOMMENSURATE PHASE OF QUARTZ
    K. Abe; A. Kakuho; T. Shigenari; Y. Sasaki; Y. Takeuchi
    FERROELECTRICS, TAYLOR & FRANCIS LTD, 155巻, 掲載ページ 347-352, 出版日 1994年, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 203-208, 出版日 1994年, 査読付
    研究論文(学術雑誌), 英語
  • Effect of Fluctuations on the Fluorescence Lifetime in Strong First Order Transitions
    T.Shigenari; K.Abe; K.Morita; Qi Ping; E.Kojima
    Ferroelectrics, 159号, 掲載ページ 209-214, 出版日 1994年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 10号, 掲載ページ 6871-6879, 出版日 1993年09月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 4号, 掲載ページ 1101-1104, 出版日 1993年04月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 49号, 掲載ページ 9931-9938, 出版日 1992年12月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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巻, 掲載ページ 475-476, 出版日 1992年, 査読付
    研究論文(国際会議プロシーディングス), 英語
  • 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, 掲載ページ 282, 出版日 1992年, 査読付
    研究論文(国際会議プロシーディングス), 英語
  • 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巻, 16号, 掲載ページ 2112-2115, 出版日 1991年04月, 査読付, 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.
    研究論文(学術雑誌), 英語
  • 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., 一般社団法人日本物理学会, 60巻, 2号, 掲載ページ 60-407, 出版日 1991年, 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.
    英語
  • 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巻, 44号, 掲載ページ 8741-8746, 出版日 1989年11月, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 7号, 掲載ページ 1199-1205, 出版日 1989年07月, 査読付
    研究論文(学術雑誌), 英語
  • OPTICAL OBSERVATION AND LIGHT-SCATTERING STUDIES ON THE INCOMMENSURATE PHASE IN QUARTZ
    T SHIGENARI; K ABE
    FERROELECTRICS, GORDON BREACH SCI PUBL LTD, 95巻, 掲載ページ 253-257, 出版日 1989年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 3号, 掲載ページ 367-370, 出版日 1987年10月, 査読付
    研究論文(学術雑誌), 英語
  • Opticla and X-ray Studies of Domain Formation in KH2PO4 Crystal
    Kohji Abe
    J. Phys. Soc. Jpn, 56巻, 2号, 掲載ページ 785-809, 出版日 1987年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 23号, 掲載ページ 4547-4560, 出版日 1986年08月, 査読付
    研究論文(学術雑誌), 英語
  • FERROELECTRIC DOMAIN FORMATION IN SHORT CIRCUITED KH2PO4
    E NAKAMURA; S USHIO; K ABE
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 53巻, 1号, 掲載ページ 403-407, 出版日 1984年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 5号, 掲載ページ 1614-1616, 出版日 1984年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 9号, 掲載ページ 3220-3226, 出版日 1984年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 9号, 掲載ページ 3074-3080, 出版日 1984年, 査読付
    研究論文(学術雑誌), 英語
  • 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巻, 9号, 掲載ページ 2783-2784, 出版日 1981年, 査読付
    研究論文(学術雑誌), 英語
  • Dielectric properties of lossy KH2PO4 crystals
    Eiji Nakamura; Kazuyuki Itoh; Satoshi Ushio; Kohji Abe; Hirohisa Yoshida
    Japanese Journal of Applied Physics, 20巻, 掲載ページ 59-62, 出版日 1981年, 査読付, 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.
    研究論文(学術雑誌), 英語

MISC

  • Raman Spectra in Ferroelectric SrTi^18^O_3_
    Kohji Abe; Keiji Yamashita Yoshiharu Tomita; Takeshi Shigenari Ruiping Wang; Mitsuru Itoh
    出版日 2002年, Ferroelectrics, 272巻, 掲載ページ 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-, 出版日 1987年, 固体物理, 22巻, 6号, 掲載ページ 6-423, 日本語, 記事・総説・解説・論説等(その他), 0454-4544, 40001388323, AN00092629

講演・口頭発表等

  • SnxSr1-xTiO3(x=0.02,0.05,0.10)の比熱の温度変化
    小貝 侑弘; 田中 広敏; 阿部 浩二; 中野 諭人
    ポスター発表, 日本語, 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, 国内会議
    発表日 2018年09月10日
  • La1-xSrxFeO3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; 阿部浩二
    ポスター発表, 日本語, 日本物理学会講演概要集, 国内会議
    発表日 2018年03月23日
  • 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
    ポスター発表, 日本語, 日本物理学会 2017 年秋季大会 概要集, 国内会議
    発表日 2017年09月23日
  • 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
    ポスター発表, 日本語, 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, 国内会議
    発表日 2017年03月18日
  • 電通大における協働型物理学演習の試み
    中村仁; 鈴木勝; 佐々木成朗; 伏屋雄紀; 小久保伸人; 高田亨; 阿部浩二
    口頭発表(一般), 日本語, 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, 国内会議
    発表日 2016年03月19日
  • 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
    口頭発表(一般), 日本語, 日本物理学会 第70回年次大会 講演概要集, 国内会議
    発表日 2015年03月21日
  • 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
    口頭発表(一般), 日本語, 日本物理学会 第70回年次大会 講演概要集, 国内会議
    発表日 2015年03月21日
  • 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
    口頭発表(一般), 日本語, 日本物理学会2014年秋季大会概要集, 国内会議
    発表日 2014年09月08日
  • 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
    口頭発表(一般), 日本語, 日本物理学会2014年秋季大会, 国内会議
    発表日 2014年09月07日
  • 『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
    口頭発表(一般), 日本語, 日本物理学会2014年秋季大会, 国内会議
    発表日 2014年09月07日
  • 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
    ポスター発表, 日本語, 日本物理学会講演概要集第69巻, 国内会議
    発表日 2014年09月
  • 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
    口頭発表(一般), 日本語, 第31回強誘電体応用会議予稿集, 京都, 国内会議
    発表日 2014年05月
  • 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
    口頭発表(一般), 日本語, ,日本物理学会第69回年次大会, 国内会議
    発表日 2014年03月27日
  • 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
    口頭発表(一般), 日本語, 日本物理学会2013年秋季大会, 国内会議
    発表日 2013年09月27日
  • 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
    口頭発表(一般), 日本語, 日本物理学会2013年秋季大会, 国内会議
    発表日 2013年09月27日
  • 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
    口頭発表(一般), 日本語, 日本物理学会 2013年秋季大会講演概要集, 国内会議
    発表日 2013年09月26日
  • 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
    口頭発表(一般), 英語, APPC12, 国際会議
    発表日 2013年07月16日
  • 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
    口頭発表(一般), 日本語, 日本物理学会概要集,日本物理学会第68回年次大会
    発表日 2013年03月
  • 二周波数注入同期パルスによる選択的コヒーレントフォノン励起と検出
    中野諭人; 森田宇亮; 佐藤智信; 松本大起; 阿部浩二; 桂川眞幸
    口頭発表(一般), 日本語, 応用物理学会,第60回応用物理学会春季学術講演会
    発表日 2013年03月
  • La_2-x_Ca_x_CoO_4_のラマン散乱スペクトルIII
    角田嘉人; 中野諭人; 阿部浩二; 堀金和正
    口頭発表(一般), 日本語, 日本物理学会概要集,日本物理学会 第68回年次大会
    発表日 2013年03月
  • 光散乱による針状ナノ粒子の形状推定
    吉木優充; 中野諭人; 阿部浩二; 佐藤進; 米沢徹; 長谷川敦司
    口頭発表(一般), 日本語, 日本物理学会概要集,日本物理学会 第68回年次大会
    発表日 2013年03月
  • C_60_ intercalated graphite (CIG)のラマン散乱スペクトル
    梅原龍一; 岡雅義; 中野諭人; 阿部浩二; 鈴木勝
    口頭発表(一般), 日本語, 日本物理学会概要集,日本物理学会 第68回年次大会
    発表日 2013年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会2012秋季大会
    発表日 2012年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会2012秋季大会
    発表日 2012年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2012年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会第67回年次大会
    発表日 2012年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会第67回年次大会
    発表日 2012年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会第67回年次大会
    発表日 2012年03月
  • 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
    口頭発表(一般), 日本語, 応用物理学会,第72回学術講演会
    発表日 2011年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会第66回秋季大会
    発表日 2011年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,第66回日本物理学会
    発表日 2011年03月
  • 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
    口頭発表(一般), 日本語, レーザー学会,レーザー学会学術講演会第31回年次大会
    発表日 2011年01月
  • 「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
    口頭発表(一般), 日本語, 日本物理学会概要集,日本物理学会65回年次大会
    発表日 2010年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会65回年次大会
    発表日 2010年03月
  • La_<2-x>Ca_xCoO_4のラマン散乱スペクトルと赤外吸収の偏光依存性
    松川恩; 中野諭人; 堀金和正; 小林利章; 鈴木勝; 阿部 浩二
    口頭発表(一般), 日本語, 日本物理学会講演概要集,2009年秋季大会
    発表日 2009年09月
  • 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
    口頭発表(一般), 日本語, 応用物理学会
    発表日 2009年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2009年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会台64回年次大会
    発表日 2009年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会概要集,日本物理学会
    発表日 2009年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会概要集,2009年秋季大会
    発表日 2009年03月
  • 学習者カルテに基づくコア・カリキュラムの学習支援とその効果
    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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,日本物理学会第64回年会
    発表日 2009年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第63回年秋季大会
    発表日 2008年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第63回年次大会
    発表日 2008年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第63回年次大会
    発表日 2008年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第62回年次大会
    発表日 2007年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第62回年次大会
    発表日 2007年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,第61回日本物理学会
    発表日 2006年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集,第61回日本物理学会
    発表日 2006年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第61回年次大会
    発表日 2006年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第61回年次大会
    発表日 2006年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,2005年秋期大会
    発表日 2005年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第60回年次大会
    発表日 2005年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第60回年次大会
    発表日 2005年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,2004年秋季大会
    発表日 2004年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,2004年秋季大会
    発表日 2004年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,2004年秋季大会
    発表日 2004年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,第59回年次大会
    発表日 2004年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2003年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2003年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2003年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2002年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2002年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2002年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2002年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2002年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集57
    発表日 2002年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,徳島,2001.9.17-20
    発表日 2001年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2001年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会講演概要集
    発表日 2001年09月
  • 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
    口頭発表(一般), 日本語, 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),
    発表日 2001年03月
  • 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
    口頭発表(一般), 日本語, 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),
    発表日 2001年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第56回年次会
    発表日 2001年03月
  • 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
    シンポジウム・ワークショップパネル(公募), 日本語, 「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
    発表日 2001年01月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第55回(9月22日-25日),
    発表日 2000年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第55回(9月22日-25日),
    発表日 2000年09月
  • 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
    シンポジウム・ワークショップパネル(公募), 日本語, 「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
    発表日 2000年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会2000年春の分科会(関西大学),
    発表日 2000年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会2000年春の分科会(関西大学)
    発表日 2000年03月
  • 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
    口頭発表(一般), 日本語, 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)
    発表日 2000年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会1999年秋の分科会
    発表日 1999年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会1999年秋の分科会
    発表日 1999年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第54回1999年秋の分科会
    発表日 1999年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第54回年次大会
    発表日 1999年03月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第54回年会
    発表日 1999年02月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会第54回年会
    発表日 1999年02月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会1998年秋の分科会
    発表日 1998年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会1998年秋の分科会
    発表日 1998年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会1998年秋の分科会
    発表日 1998年09月
  • 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
    口頭発表(一般), 日本語, 日本物理学会,日本物理学会1998年秋の分科会
    発表日 1998年09月

担当経験のある科目_授業

  • 環太平洋圏の社会と文化
    The University of Electro-Communications
  • 環太平洋圏の社会と文化
    電気通信大学
  • 環太平洋圏の社会と文化
    電気通信大学

所属学協会

  • 日本物理学会

共同研究・競争的資金等の研究課題

  • 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
    研究代表者
    研究期間 2016年 - 2018年
  • 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
    研究期間 2014年07月 - 2015年08月
  • 不整合相転移の起源と位相揺らぎに関する新しい視点
    重成 武; DMITRIEV S. V.; 阿部 浩二; DMITRIER S. V.; S. V. Dmitriev
    日本学術振興会, 科学研究費助成事業, 電気通信大学, 基盤研究(C), 本研究の目的は,不整合相固有の素励起である位相揺らぎ(Phason)の影響が、これまで考えられていたより遙かに重要な効果をもたらすことを実証することにある.このモデルでは不整合相の出現に伴う変調波の位相揺らぎが、回折実験で観測されるべき衛星反射の強度(Debye-Waller因子)を極めて小さくするため,或る温度Tiでの衛星反射の出現は必ずしも不整合相への転移を意味せず,実際の構造変化はTiより高い温度で起こり得る事を主張している.その典型例が,各種デバイスの絶縁体基板としてまた圧電振動子として応用面でも極めて重要な物質であるSiO2(水晶)である.しかしこの問題自体は(変位型)不整合相転移一般にあてはまる基本的問題である. 本研究の成果の概要は次の3点である. [1]低波数ラマン散乱強度の変化の測定:高温相であるβ相ですでに不整合相が発生するならば,ソフト化するフォノン分枝(C_<44>TA分枝)の分散関係に変化が現れるはずであり,2次ラマン散乱強度の温度異存に変化が現れることが期待される.実際にTiより約30K高い温度からその積分強度およびlineshapeに異常が現れる事が見いだされた. [2]分子動力学(MD)計算によるSiO2(水晶)の3倍周期構造の出現の証明:上記のモデルが正しければ不整合相は(観測されている30倍に近い長周期でなく)3倍周期に近い構造が,β相と思われている温度で出現するはずである.このことを第1原理計算より得られたTsuneyukiポテンシャルを用いたMD計算を用いて明らかにした. [3]弾性ヒンジ(蝶番)モデルによる不整合相のダイナミクスの研究.誘電体の相転移の特徴は、原子団が剛体に近いクラスタとして回転的変位をすることにあることに注目し,この特徴を生かしたモデルをたて計算機simulationによって不整合相での構造の変化のダイナミクスを一般的に解析した.また回転的自由度が負のポワソン比を与える可能性を示した. これらの結果により,単純な平進構造を持つ通常な結晶に比べ,周期的変調を受けた構造(不整合相)を持つ相での物性には変調の位相揺らぎが大きな影響をもたらしていることが明らかになった., 11640311
    研究期間 1999年 - 2001年
  • 金属単結晶表面上の酸化物単結晶薄膜の物性の研究
    村田 好正; 阿部 浩二; 山田 千樫; 重成 武
    日本学術振興会, 科学研究費助成事業, 電気通信大学, 基盤研究(B), 1.格子の整合性と相転移を利用してRu(0001)上にα-Al_2O_3(膜厚9Å)、Ni(111)上にSiO_2(40Å)の高品質単結晶薄膜の作製に成功し、走査トンネル分光法(STS)で膜厚が薄くなるにつれて酸化物のバンドギャップが狭くなることを見いだした。2.STS測定にはいろいろ問題が残るので、α-Al_2O_3/Ru(0001)について5〜40Åのいろいろな膜厚の酸化膜を作製し、角度分解電子エネルギー分光法を用いてこのことを確認した。このバンドギャップナロイングは電子系の多体効果で説明できた。3.バンドギャップナロイングを利用すると、この酸化膜上に遷移金属が層状成長すると予測し、α-Al_2O_3(9Å)/Ru(0001)では1原子層(1ML)、SiO_2/Ni(111)では5MLのPtの金属超薄膜を作ることに成功した。バルクの単結晶酸化膜上ではこのような遷移金属超薄膜はできず、クラスター化する。4.Pt(1ML)/α-Al_2O_3(9Å)/Ru(0001)の白金超薄膜は準安定状態にあり、STS測定で高い局所電場を印加するとクラスター化する。5.これらのPt超薄膜に飽和吸着したCO分子の反射吸収赤外スペクトルを観測し、Pt超薄膜の特異な電子物性を反映した結果を得た。6.エリプソメトリーで測定した膜厚40ÅのSiO_2/Ni(111)について高輝度の放射光を用いた微小角入射X線回折により酸化膜の構造を調べた。{20}ロッドの強度分布曲線からSiO_2は(1)膜厚が30Åであること、(2)β相の単結晶水晶でることが判明した。詳細な測定と解析は続行中である。7.回転体陰極で高輝度化したX線回折計を用いた2次元マップの測定から、界面に多結晶シリサイドのバッファー層(膜厚10Å)の存在が判明した。さらにこの界面物質の結晶形の決定に効果的な放射光の白色X線を用いた微小角入射のラウエパターンの測定に成功し、単結晶薄膜の生成機構を知る上での重要な知見を得た。, 11440090
    研究期間 1999年 - 2000年
  • 氷単結晶中のプロトンダイナミクスと融解の研究
    重成 武; 阿部 浩二
    日本学術振興会, 科学研究費助成事業, 電気通信大学, 基盤研究(C), 本研究では,先に我々の研究室で開発した2-ナフトールを蛍光プローブとしたピコ秒パルスレーザー励起蛍光法による実験によって,氷中のプロトンの動きを光学的に探る方法を確立した.本研究課題によって次のことが明らかになった. (1)パルス励起後の蛍光の減衰曲線から得られる寿命とそのうちの2成分の強度比の温度変化はともにESPT(励起状態プロトン移動)モデルでよく説明できる.(2)氷中のプロトンの移動度は、L欠陥の移動度の増加を反映した120K以上で増大するが,その影響は中世励起ナフトールからの蛍光寿命の温度変化として検出できる.(3)72Kで起こるプロトンの秩序化相転移(1h相からX1相への相転移)が蛍光寿命の短縮化として検出された.このことは強い1次の相転移においてこの方法が有効なことを明らかにした.また(4)これまでKOHドープの氷のみで観測されたこの相転移が,KOHがなくても局所的には起こっていることを示しておりこの相転移が氷本来の性質であること,いいかえれば巨視的にはIce-Ruleによる制約により相転移が起きにくくなっていることを示唆している.(5)ブローブとしての2-ナフトールの氷結晶中への取り込まれ方を明らかにするため,不純物の少ない2-ナフトール結品を真空昇華法により作成しそのスペクトルと,氷中のスペクトルとの比較からその微細構造の同定を行った.その結果ゼロフォノン線のシフト量の異なるいくつかのタイプのスペクトルがあらわれることが判明し今後の研究の基礎となるデータが得られた.融解に関する研究はこれらをふまえて継続中である. これらの結果はいくつかの論文に公表した.特に1996年米国NewHampshireでおこなわれた国際会議Physics and Chemistry of Iceでの発表の結果はJ.Phys.Chem.に印刷中である., 07640438
    研究期間 1995年 - 1996年
  • 蛍光寿命測定による結晶の融解における前駆現象と緩和過程の研究
    重成 武; 阿部 浩二; 竹内 義雄; 佐々木 行彦
    日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(C), 【1】スクロース結晶の融解と蛍光寿命の測定.分子性結晶であるスクロース(庶糖)の単結晶を用い,その融解点に至るまでの,X線,ラマン及び蛍光スペクトルを詳細に調べた.蛍光バンドに大きな変化が現れ,ラマンスペクトルの偏光依存性とX線ラウエスポットは融解点の約20K下から失われることを見いだした.一方,蛍光寿命も融解点の下約25Kから短縮化が始まり,10K下までくるとさらに顕著に短縮化する.即ち寿命の変化は、融解に先立つ結晶の並進対称性の消失を反映していることが分かった.これらの事実は,この短縮化が分子性結晶の分子間振動の揺らぎの増大の結果起こっていることを示している.この研究で見いだされた“critical speeding-up"は融解現象の前駆現象の初めての観測であり,Ferroelectrics誌に印刷中である.【2】氷(Ice,Ih)単結晶中のプロトンのdynamicsと融解と関する研究を行い,特にβ-ナフトール(2-Naphthole)分子をdopeした単結晶を育成し,氷からの蛍光を観測可能にした.氷は水素結合を含む単純な構造を持つ結晶であるが,その特異な性質はプロトンの動きと秩序化に関係している.130Kから200Kにかけ5nsから2nsへの階段状の寿命の短縮化が見いだされた.これは励起状態のnaphthol分子の周囲の氷中のL欠陥へのプロトン移動・緩和によるものと考えられ,プロトンに関する新しい研究手段として有望であることが明らかになった.融解点近傍での蛍光寿命はβナフトールに関しては予測に反し融解直前まで変化は現れず,液体になると不連続に増大することが見いだされた.【3】ビフェニル結晶の相転移に関する研究.ビフェニルの相転移は40Kの低温にあり2次の構造相転移をする.この相転移に関しても転移点で極小となる蛍光寿命が確認された.一方533nmの鋭いゼロフォノン線の発光寿命が温度変化しないことからもこの短縮化が相転移の影響であることを明らかに示している. これらの結果は,本研究法が,結晶中の局所的な構造の揺らぎを敏感に検知できることを実証したものであり当初の目的をほぼ達成することができた.結果は日本物理学会(1992.3,1992.10,1993.4,1993.10,1994.3)及び科研費総合研究(A)“水素結合を持つ結晶の相転移の新しい視点"の研究会(1992.11),第8回強誘電体国際会議(1993.8)等で発表した.また1994.3の物理学会ではシンポジウム"ピコ秒フェムト秒パルス光による相転移研究の新しい展開"において講演を行った., 04640329
    研究期間 1992年 - 1993年