• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Thoretical Study on First-principles Calculation of Lattice Dynamics and Pressure-Induced Superconductivity

Research Project

Project/Area Number 06640476
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 固体物性Ⅱ(磁性・金属・低温)
Research InstitutionOsaka University

Principal Investigator

SUZUKI Naoshi  Osaka Univ., Fac.Engi.Sci., Professor, 基礎工学部, 教授 (40029559)

Co-Investigator(Kenkyū-buntansha) SHIRAI Masafumi  Osaka Univ., Fac.Engi.Sci., Assoc.Professor, 基礎工学部, 助教授 (70221306)
Project Period (FY) 1994 – 1996
Project Status Completed (Fiscal Year 1996)
Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Keywordssolid iodine / solid bromine / FLAPW method / electronic band structure / frozen-phonon method / electron-lattice interaction / lattice dynamics / superconductivity / 圧力誘起非金属-金属転移
Research Abstract

Electronic band strucutures, electron-lattice interaction, lattice dynamics and superconductivity in high pressure FCC phase of solid iodine and bromine are studied in detail on the basis of the first-principles full-potential LAPW (FLAPW) method and the semi-empirical tight-binding method. The main results are summarized as follows.
1.The obtained band structures have three hole Fermi surfaces, and hence the FCC solid iodine and bromine are typical hole metals. The density of states at the Fermi energy N (E_F) decreases with increasing pressure.
2.Electron-lattice coupling has been evaluated microscopically by the tight binding method in which transfer energies and their derivatives are determined so as to reproduce the first-principles band structures obatined by the FLAPW method. The Fermi surface average of squared electron-lattice coupling <xi^2> increases considerably as the pressure increases.
3.The frequencies of the longitudinal (L) and the transverse (T) phonon modes at the X (0 … More ,0,2pi/a) point in the Brillouin zone (BZ) have been calculated by the frozen-phonon method. The obtained frequencies show hardening with increasing pressure.
4.The phonon spectrum of the whole BZ have been calculated by taking accout of the electron-lattice interaction and by considering only the nearest neighboring short range forces which were determined to reproduce omega_L and omega_T at the X point obtained by the frozen-phonon method. The average of phonon frequency <omega> and that of squared phonon frequency <omega^2> increases significantly as the pressure increases.
5.The value of N (E_F) <xi^2> increases considerably with increasing pressure, but <omega^2> increases more rapidly than N (E_F) <xi^2> as pressure increases. Therefore the dimensionless electron-phonon coupling lambda = N (E_F) <xi^2> /M <omega^2> becomes a decreasing function of pressure. As the results the superconducting transition temperature T_c also decreases with increasing pressure.
The magnitude of T_c is in order of 1 K,which agrees with the experimental results. But, the calculated pressure-dependence of T_c is diffrent from that of observations in iodine. This discrepancy may suggest a necessity of treating the electron-lattice interaction in more first-principles manner. Less

Report

(4 results)
  • 1996 Annual Research Report   Final Research Report Summary
  • 1995 Annual Research Report
  • 1994 Annual Research Report
  • Research Products

    (25 results)

All Other

All Publications (25 results)

  • [Publications] T. Oda: "First-Principles Study on Lattice Dynamics and Electron-Phonon Interaction in an Oxide Spinel LiTi_2O_4" Physica B. 219 & 220. 451-453 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] N. Suzuki: "First-Principles Calculation of Lattice Dynamics and Electron-Phonon Interaction in High Pressure Phase of Solid Iodine" Physica B. 219 & 220. 454-456 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] H. Sakamoto: "Application of Frozen-Phonon Method to Lattice Dynamics in FCC Solid Iodine" J Phys. Soc. Jpn.65. 489-495 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] H. Sakamoto: "Pressure Effects on Electronic Structure and Electron-Lattice Interaction of Cubic Phase of Solid Iodine" J Phys. Soc. Jpn.64. 3860-3870 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] T. Oda: "Electron-Phonon Interaction, Lattice Dynamics and Superconductivity of an Oxide Spinel LiTi_2O_4" J. Phys. : Condens. Matter. 6. 6997-7012 (1994)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] T. Oda: "Role of Electron-Phonon Interaction in Lattice Dynamics and Superconductivity of Oxide Spinel LiTi_2O_4" J. Superconductivity. 7. 555-558 (1994)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] N.Suzuki: "First-Principles Calculation of Lattice Dynamics and Electron-Phonon Interaction in High Pressure Phase of Solid Iodine" Physica B. 220. 454-456 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] T.Oda: "First-Principles Study on Lattice Dynamics and Electron-Phonon Interaction in an Oxide Spinel LiTi_2O_4" Physica B. 220. 451-453 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] H.Sakamoto: "Application of Frozen-Phonon Method to Lattice Dynamics in FCC Solid Iodine" J.Phys.Soc.Jpn.65. 489-495 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] H.Sakamoto: "Pressure Effects on Electronic Structure and Electron-Lattice Interaction of Cubic Phase of Solid Iodine" J.Phys.Soc.Jpn.64. 3860-3870 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] T.Oda: "Electron-Phonon Interaction, Lattice Dynamics and Superconductivity of an Oxide Spinel LiTi_2O_4" J.Phys. : Condens.Matter. 6. 6997-7012 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] T.Oda: "Role of Electron-Phonon Interaction in Lattice Dynamics and Superconductivity of Oxide Spinel LiTi_2O_4" J.Superconductivity. 7. 555-558 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] T.Oda: "First-Principles Study on Lattice Dynamics and Electron-Phonon Interaction in an Oxide Spinel LiTi_2O_4" Physica B. 219&220. 451-453 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] N.Suzuki: "First-Principles Calculation of Lattice Dynamics and Electron-Phonon Interaction in High Pressure Phase of Solid Iodine" Physica B. 219&220. 454-456 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] T.Oda: "First-Principles Study on Lattice Dynamics and Electron-Phonon Interaction in an Oxide Spinel LiTi_2O_4" Physica B. (in press). (1996)

    • Related Report
      1995 Annual Research Report
  • [Publications] N.Suzuki: "First-Principles Calculation of Lattice Dynamics and Electron-Phonon Interaction in High Pressure Phase of Solid Iodine" Physica B. (in press). (1996)

    • Related Report
      1995 Annual Research Report
  • [Publications] H.Sakamoto: "Application of Frozen-Phonon Method to Lattice Dynamics in FCC Solid Iodine" J.Rhys.Soc.Jpn.65. 489-495 (1996)

    • Related Report
      1995 Annual Research Report
  • [Publications] H.Sakamoto: "Pressure Effects on Electronic Structure and Electron-Lattice Interaction of Cubic Phase of Solid Iodine" J.Phys.Soc.Jpn.64. 3860-3870 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] T.Oda: "Electronic Band Structure of Sulphide Spinels CuM_2S_4(M=Co,Rh,Ir)" J.Phys.: Condens.Matter. 7. 4433-4445 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] Y.Tagawa: "Optical Absorption Spectra in One-Dimensional Mixed-Valence Complexes Pt-X(X=Cl,Br.I)" J.Phys.Soc.Jpn.64(in press). (1995)

    • Related Report
      1994 Annual Research Report
  • [Publications] Y.Tagawa: "Correlation Effect on Optical Absorption in One-Dimensional Peierls-Hubbard Systems" J.Phys.Soc.Jpn.64(in press). (1995)

    • Related Report
      1994 Annual Research Report
  • [Publications] T.Oda: "Electron-Phonon Interaction,Lattice Dynamics and Superconductivity of an Oxide Spinel LiTi_2O_4" J.Phys.:Condens.Matter. 6. 6997-7012 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] T.Oda: "Role of Electron-Phonon Interaction in Lattice Dynamics and Superconductivity of Oxide Spinel LiTi_<>O_4" J.Superconductivity. 7. 555-558 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] Y.Nishio: "Role of Electron-Lattice Interaction in Layered Transition-Metal Dichalcogenide 2H-NbS_2.I.Phonon Anomaly and Superconductivity" J.Phys. Soc. Jpn.63. 156-167 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] T.Kawamoto: "Dipole-Dipole Interaction and Field-Induced Phase Transition in Molecular Antiferromagnet MOTMP" J.Phys.Soc.Jpn.63. 3158-3162 (1994)

    • Related Report
      1994 Annual Research Report

URL: 

Published: 1994-04-01   Modified: 2020-05-15  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi