| Project/Area Number |
12640552
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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 |
機能・物性・材料
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
ATOU Toshiyuki TOHOKU UNIVERSITY, INSTITUTE FOR MATERIALS RESEARCH, RESEARCH ASSOCIATE, 金属材料研究所, 助手 (40241567)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | HIGH-PRESSURE / TRANSITION METAL OXIDE / ELECTRONIC TRANSITION / PHASE TRANSITION / MOTT TRANSITION / COBALT MONOXIDE / ELECTRIC RESISTIVITY / DIAMOND ANVIL CELL / Mott転移 |
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| Research Abstract |
At ambient pressure, 3d transition metal monoxides are typical Mott insulator with the antiferromagnetically ordered, localized magnetic moment due to strong electron correlation. Under very high pressure, however, metallization accompanied by magnetic collapse is anticipated to take place owing to marked band width broadening as well as intesified ligand field.
Recently, we have confirmed structural phase transition of MnO and CoO at 90 and 81 Gpa, respectively, using a diamond anvil cell. To clarify the nature of these phase transitions, electrical resistivity measurements were carried out in the range of 100 Gpa. Drastic decrease of the electrical resistivity (6 orders of magnititude) of cobalt monoxide was observed at 93 Gpa and below 220 K. Also, three phases with different electrical resistivity could be found. These observations are well consistent with the previous X-ray measurements. The high pressure phase of cobalt monoxide showed metallic behavior under high pressure.
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