Study of Surface Spin Wave by use of Variable Temperature Conversion Electron Spectrometer for Mossbauer Spectroscopy

Research Project

Project/Area Number	60540198
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	固体物性
Research Institution	Tokyo Institute of Technology
Principal Investigator	TAKETANI Hiroshi (1986) Tokyo Institute of Technology, Faculty of Science, Professor, 理学部, 教授 (40016043) 鳥山保 (1985) 東京工業大学, 理学部, 助手
Co-Investigator(Kenkyū-buntansha)	HASHIMOTO Takasu Tokyo Institute of Technology, Faculty of Science, Associated Proffesor, 理学部, 助教授 (70016103) HISATAKE Kazuo Jissen Women's University, Professor, 家政学部, 教授 (70016012)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1985: ¥1,500,000 (Direct Cost: ¥1,500,000)
Keywords	Variable Temperature / Conversion Electron / Mossbauer Spectroscopy / Iron Oxide Film / 表面スピン波
Research Abstract	It was an aim of this study to measure the difference between a temperature dependence of magnetization at surface and that in bulk of the samples; <Fe_(1-x)O> (Wustite), <Fe_3O_4> (Magnetite) and <FeF_2> (Iron fluoride), by use of temperature variable conversion electron Mossbauer spectroscopy. The enriched <^(57)Fe> oxide thin film was made under the <O_2> partial pressure of <10^(-16.5)> atm. and at the temperature of 800 C. This film was observed to be composed of <Fe_3O_4> , <Fe_(1-x)O> and -Fe by use of a He + 10% <CH_4> proportional counter for Conversion Electron Mossbauer Spectroscopy. After then, Mossbauer spectra for the film have been measured with the electron spectrometer mentioned above. For 6.6 keV, 7.15keV and 7.3 keV, the spectra have been obtained at 5, 6 and 2 different temperatures, respectively. Although the statistics of these were not so satisfactory because the Mossbauer source used was not strong(30 mCi), the following results were obtained. 1) This iron oxide film is composed of <Fe_3O_4> , <Fe_(1-x)O> and -Fe from surface to deeper region sequentially. 2) The transition temperature of <Fe_(1-x)O> is between 176 K and 206 K and the hyperfine field of <Fe_(1-x)O> nearly coincides with that of <Fe_3O_4> at lower temperature than 156 K. 3) It is observed that in 7.3 keV spectrum,measured at 78 K, there is a component of <Fe_3O_4> with the hyperfine field larger than those in the other energies at the same temperature. Nextly, the same measurements for <Fe_3O_4> enriched film will be done with the Mossbauer source stronger than the present in order to confirm the third result.