1991 Fiscal Year Final Research Report Summary
Researches on Transport Property and Electronic Structure of Metallic Superlattices, Metal Oxides and Metal Halogenides
| Project/Area Number |
01460036
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | Iwaki Meisei University |
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Principal Investigator |
TANUMA Sei-ichi Iwaki Meisei University, Department of materials Science Prof., 理工学部物性学科, 教授 (70013448)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIKAWA Takuma Iwaki Meisei University, Dept. Materials Science Assoc. Prof., 理工学部物性学科, 助教授 (80016138)
TAKASHIGE Masaaki Iwaki Meisei University, Dept. Electronic Engineering Prof., 理工学部電子工学科, 教授 (70114527)
YOSIDA Yositaka Iwaki Meisei University, Dept. Materials Science Assoc. Prof., 理工学部物性学科, 助教授 (20107444)
SAWADA Shozo Iwaki Meisei University, Dept. Electronic Engineering Prof., 理工学部電子工学科, 教授 (60015998)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Metallic superlattice / Metal oxide / Metal halogenide / Graphite intercalation compound / Oxide superconductor / Microwave conductivity / Europium - strontium superlattice |
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| Research Abstract |
(1)As one of the main research equipments for joint use in the Department of Materials Science, a MBE(molecular beam epitaxy)film growing machine was installed in 1988. The Grant was partially used for activating this MBE work, i. e., a study of metallic superlattice. Europium and strontium were chosen as the superlattice elements, because that Eu has a spin moment and Sr which is very similar to Eu in atomic size and divalency has no spin, so that interesting magnetic behaviors dependent on superlattice periods are expected. By using BaF_2 (111)face as the substrate, Sr was grown epitaxially and Eu followed. The epitaxy was proved by RHEED and X-ray diffraction. Below about 1 OK, a ferromagnetic magnetization was observed as a preliminary measurement.
(2) The most important metal oxides at present should be CUO_2-based high Tc superconductors. An effective simple controlling treatment for the oxygen concentration was found in Y_1Ba_2CU_3O_y, which included a heating in the normal-atmos
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phere and a successive quenching.
Researches on the conduction property of yttrium- and bismuth- oxides superconductors in the microwave frequency range were done. Different from the DC measurement, the resistance measurement iri microwave frequency range is hardly influenced by grain boundaries. It was found that the measured surface resistance showed an anomaly which related to an uncommomly large effective surface area.
(3)The bromine and ICI intercalated graphite compounds were taken up as the metal halogenides, Br_2 or ICl were intercalated into KIKAFILM of Nihon Carbon Co. (an equivalent material to grafoil of the Union Carbide Co.)in the room temperature by hanging above the surface of solution of halogen and CCl_4. During the reaction term, resistance, magnetoresistance and Hall effect were in-situ measured. By analysing the obtained data, the reaction-time dependence of the concentrations of conduction holes and electrons was deduced.
GaCl_3 was intercalated by co-sealing with chlorine gas and a NIKAFILM chip into a glass ampule. The first and second stage compounds were obtained at the room temperature. Higher stage compound were made by puming the ampule which included a low stage compound and heating it at the temperature of several tens ﾟC. The stage dependence of the conductivity of GaCl_3-GICs is to be investigated in order to compare to the proposed theory of the head investigator. Less
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