| Project/Area Number |
17540341
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Chuo University |
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Principal Investigator |
SATO Hirohiko Chuo University, Faculty of Science and Engineering, Associate Professor (90262261)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | transition metal oxides / highly correlated system / hydrothermal synthesis / crystal structure / magnetism / electric conduction / low temperature / 強相関電子系 / 低温物性 / 物性実験 / 固体化学 / 結晶成長 |
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| Research Abstract |
Transition metal oxides are interesting system for their variety of electronic properties such as ferromagnetism, superconductivity and giant magnetoresistance. These discoveries are very important not only for its applications but also from a fundamental point of view of solid-stabs physics. In our country, most of studies of transition metal oxides have been, so far, concentrated on perovskite-type compounds. For further advance in this field, it is also important to discover more and more new transition metal oxides including non-perovsltite type compounds. hi this project, I succeeded to synthesize several new transition metal oxides without pemvskite structure using hydrothermal technique. The detailed results are as Mows.
1. Novel hollandite type transition metal oxides.
We discovered new hollandite type transition metal oxides, Rb_<15>Mo_8O_<16>, K_2Rh_8O_<16> and Rb_<12>Rh_8O_<16>. Measurements of the magnetization and the conductivity revealed that the electrons are localized on Mo4 clusters in the Mo-hollandite, whereas the Rh-hollandites have characteristics of highly correlated metal
2. Anomalous coexistence of metallic conduction and spin glass magnetism in a novel pyrochlore ruthenate.
We discovered a novel ruthenium pyrochlore Ca_2Ru_2O_7. The magnetic susceptibility reveals that Pauli paramagnetism and Curie-Weiss type paramagnetism. Furthermore, the localized spins undergo spin glass transition at low temperature.
3. Anomalous magnetism in new iron boroxide.
We succeeded to synthesize a new iron boroxide Fe3_B_7O_<13>(OH) for the first time. Measurements of the magnetization revealed that this compound undergoes successive magnetic phase transition at low temperature. The magnetic phases are strongly dependent on the orientation of magnetic fiekl.
4. Various magnetic phases in lithium ruthenates.
We synthesized several Li-Ru-O ternary compounds and discovered various interesting magnetic phases such as spin glass.
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