Research of Metal-Nonmetal Transition of Electron-Hole System under Size Quantization in Bi in Strong Magnetic Field

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06640483
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 固体物性Ⅱ(磁性・金属・低温)
• Research Institution: KYUSHU UNIVERSITY
• Principal Investigator: FUKAMI Takeshi Kyushu University, Faculty of Science, Associate professor, 理学部, 助教授 (20037261)
• Co-Investigator(Kenkyū-buntansha): ICHIKAWA Fusao Kyushu University, Faculty of Science, Research Associate, 理学部, 助手 (30223085)
• Project Period (FY): 1994 – 1995
• Keywords: Metal-nonmetal transition / seze effect / bismuth

Research Abstract

By a vacuum evaporation technique, bismuth thin films were prepared on BaF_2 single crystal substrate with (111) surface. To improved the degradation of films due to a misfiting of the lattice constant between Bi and BaF_2 by about 3.6%, the heat treating was carried out at a temperature just below the melting point(273ﾟC). By X ray analysis, it was confirmed that the films were single crystal and had a preferred orientation perpendicular to the surface of the substrate. The experimental results are summarized as follows :
(1) Bi thin films were prepared reproducibly on BaF_2 single crystal substrate at around 80ﾟC.
(2) Flat surface with layring growth were obtained for films with different thickness from 140*to2800*.
(3) A classical size effect was confirmed for the thickness and temperature dependence of electrical transport for the films with different thickness from 140* to 2800*.
(4) The size quantization with a period of de Broglie wave length was also confirmed.
(5) The metal semiconductor transition was confirmed in the thickness dependence of carriers between 420* and 560*.