First-principles molecular-dynamics study of polymorphism in liquids and glasses

2008 Fiscal Year Final Research Report

• Project/Area Number: 18740266
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Biophysics/Chemical physics
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: MORISHITA Tetsuya National Institute of Advanced Industrial Science and Technology, 計算科学研究部門, 研究員 (10392672)
• Project Period (FY): 2006 – 2008
• Keywords: ポリアモルフィズム / 過冷却液体 / アモルファス / Si / 分子動力学 / 第一原理

Research Abstract

アモルファスや液体状態のシリコンが、温度や圧力に対してどのように変化するかを、コンピュータシミュレーションにより解明した。液体シリコンに関しては、(1)融点から500度近く過冷却すると水と同様な密度極大が生じること、及び(2)そのような過冷却下では、液体構造に著しい不均一性が現れることを初めて明らかにした。またアモルファスシリコンに関しては、(3)通常のアモルファスシリコンを加圧して得られる高密度アモルファスシリコンが金属的であることを示した。

Research Products

• [Journal Article] Structural, electronic, and vibrational properties of high-density amorphous silicon : A first-principles molecular dynamics study (2009)
  • Author(s): T. Morishita
  • Journal Title: Journal of Chemical Physics vol.130 Pages: 194709
  • Peer Reviewed
• [Journal Article] Structural and dynamical heterogeneity in deeply supercooled liquid silicon (2008)
  • Author(s): T. Morishita
  • Journal Title: Physical Review E vol. 77 Pages: 020501( R )
  • Peer Reviewed
• [Journal Article] Formation of single- and double-layer silicon in slit pores (2008)
  • Author(s): T. Morishita, K. Nishio, and M. Mikami
  • Journal Title: Physical Review B vol. 77 Pages: 081401( R )
  • Peer Reviewed
• [Journal Article] Structural heterogeneity and non-exponential relaxation in supercooled liquid silicon (2008)
  • Author(s): T. Morishita
  • Journal Title: AIP Conference Proceedings vol. 982 Pages: 804
  • Peer Reviewed
• [Journal Article] Enhanced sampling via strong coupling to a heat bath : Relationship between Tsallis and multicanonical algorithms (2007)
  • Author(s): T. Morishita and M. Mikami
  • Journal Title: Journal of Chemical Physics vol. 127 Pages: 034104
  • Peer Reviewed
• [Journal Article] Isothermal-isobaric first principles molecular dynamics : application to polymorphism in liquids and amorphous materials (2007)
  • Author(s): T. Morishita
  • Journal Title: Molecular Simulation vol. 33 Pages: 5
  • Peer Reviewed
• [Journal Article] How does terahedral structure grow in liquid silicon upon supercooling? (2006)
  • Author(s): T. Morishita
  • Journal Title: Physical Review Letters vol. 97 Pages: 165502
  • Peer Reviewed
• [Journal Article] Multiple amorphous-amorphous transitions
  • Author(s): T. Loerting, V. V. Brazhkin, and T. Morishita
  • Journal Title: Advances in Chemical Physics (in press)
  • Peer Reviewed
• [Presentation] 第一原理分子動力学法を用いたポリアモルフィズムの研究 (2009)
  • Author(s): 森下徹也
  • Organizer: 日本物理学会第64回年次大会
  • Place of Presentation: 立教学院池袋キャンパス
  • Year and Date: 2009-03-29
• [Presentation] Structural and dynamical heterogeneity in supercooled liquid silicon (2008)
  • Author(s): Tetsuya Morishita
  • Organizer: International Conference UCGP2008
  • Place of Presentation: Kyoto, Japan
  • Year and Date: 2008-11-26
• [Presentation] アモルファスシリコンの半導体-金属転移 (2008)
  • Author(s): 森下徹也
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 岩手大学
  • Year and Date: 2008-09-23
• [Presentation] First-Principles Molecular-Dynamics Investigation of Polymorphism in Liquids and Amorphous Materials (2008)
  • Author(s): Tetsuya Morishita
  • Organizer: MSSMBS 2008 International Workshop
  • Place of Presentation: Moscow, Russia
  • Year and Date: 2008-09-11
• [Presentation] スリット状細孔におけるナノシートSiの形成シミュレーション (2008)
  • Author(s): 森下徹也, 西尾憲吾, 三上益弘
  • Organizer: 第63回日本物理学会年次大会
  • Place of Presentation: 近畿大学
  • Year and Date: 2008-03-23
• [Presentation] Structure and dynamics of supercooled liquid silicon under pressure : A first-principles molecular-dynamics study (2008)
  • Author(s): Tetsuya Morishita
  • Organizer: 2008 APS Annual March Meeting
  • Place of Presentation: New Orleans, U.S.A.
  • Year and Date: 2008-03-11
• [Presentation] 過冷却液体Siの構造及びダイナミクスの不均一性 (2007)
  • Author(s): 森下徹也
  • Organizer: 第21回分子シミュレーション討論会
  • Place of Presentation: 金沢歌劇座
  • Year and Date: 2007-11-26
• [Presentation] Structural heterogeneity and non-exponential relaxation in supercooled liquid silicon (2007)
  • Author(s): Tetsuya Morishita
  • Organizer: The 5th International Workshop on Complex Systems
  • Place of Presentation: Sendai, Japan
  • Year and Date: 2007-09-27
• [Presentation] 過冷却液体シリコンにおける構造及びダイナミクスの不均一性II (2007)
  • Author(s): 森下徹也
  • Organizer: 第62回日本物理学会年次大会
  • Place of Presentation: 北海道大学
  • Year and Date: 2007-09-24
• [Presentation] 過冷却液体シリコンの構造及びダイナミクスの非一様性 (2007)
  • Author(s): 森下徹也
  • Organizer: 日本物理学会春季大会
  • Place of Presentation: 鹿児島大学
  • Year and Date: 2007-03-20
• [Presentation] 過冷却液体シリコンの構造及びダイナミクスの非一様性 (2006)
  • Author(s): 森下徹也
  • Organizer: 日本物理学会春季大会
  • Place of Presentation: 千葉大学
  • Year and Date: 2006-09-25