Phonon-state-densities in charcogenides studied from magnetic field dependences of spin-lattice relaxation rates.

1987 Fiscal Year Final Research Report Summary

• Project/Area Number: 60460036
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 固体物性
• Research Institution: Science University of Tokyo
• Principal Investigator: MISU Akira Department of Physics, Faculty of Science, Science University of Tokyo, 理学部, 教授 (30011513)
• Co-Investigator(Kenkyū-buntansha): KOBATASHI Masaaki Department of Physics, Faculty of Science, Science University of Tokyo, 理学部, 助手 (60084323)
• Project Period (FY): 1985 – 1987
• Keywords: Chalcogenides / Amorphous AsSe / Faraday rotation / Cu_2O / Zeeman splitting / 反磁性シフト

Research Abstract

An apparatus for Faraday rotation measurements in pulse magnetic fields was built, and was tested. It can be used to observe time dependent phenomena in magnetic fields. With this apparatus, experiments were performed on amorphous As-Se chalcogenides and those doped with Mn^<2+> ions. Bindins of the amorthous material and electronic states of the Mn^<2+> ions in the material were determined. Results were in agreement with results of Raman scattering and ESR measurements.
In a submegagauss magnetic field range, the yellow series excitons in Cu_2O were investigated. On the n=2 exction, the Zeeman splitting and the diamagnetic shift were observed for the first time. On the n=3 exction, the diamagnetic shif changed into a linea magnetic field dependence of the Landau level, and was found to coincide with a calculated result on an hydrogen atom. In low magnetic fields generated by a superconducting magnet, the diamagnetic coupling was found to work between different n excitons.