Project/Area Number |
09440188
|
Research Category |
Grant-in-Aid for Scientific Research (B).
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Petrology/Mineralogy/Science of ore deposit
|
Research Institution | Okayama University |
Principal Investigator |
KATSURA Tomoo Institute for Study of the Earth's Interior, Okayama University, Associate Professor, 固体地球研究センター, 助教授 (40260666)
|
Co-Investigator(Kenkyū-buntansha) |
KANZAKI Masami Institute for Study of the Earth's Interior, Okayama University, Associate Professor, 固体地球研究センター, 助教授 (90234153)
|
Project Period (FY) |
1997 – 2000
|
Project Status |
Completed (Fiscal Year 2000)
|
Budget Amount *help |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 2000: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1998: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥6,500,000 (Direct Cost: ¥6,500,000)
|
Keywords | Thermal diffusivity / Angstrom method / periclase / forsterite / zircona / corundum / オングストローム / 格子振動 / ウムクラップ / 温度依存性 / 圧力依存性 / ウムクラップ過程 / 高温高圧 / 安定化ジルコニア / 高圧 / 高温 / かんらん石 / 非調和性 |
Research Abstract |
In this study, first we constructed a measurement system of thermal diffusivity by Angstrom method We constructed a heating system using a programmable power source which can modulate electric voltage such that electric power sinusoidally changes. Using an external trigger, we measure emf of two thermocouples inserted to a sample to determine phase lag between temperature oscillations at two different points. The positions of two thermocouples are measured opetically. Thermal diffusivity is calculated from these positions and the phase lag. We measured thermal diffusivity of periclase, forsterite, zircona and corundum at high pressures and temperatures. Thermal diffusivity of all of these materials decreases with increasing temperature and increases with increasing temperature. Reciprocal thermal diffusivity of periclase is linearly increases with increasing temperature as is the case of simple materials. Its gradient decreases with increasing pressure. Reciprocal thermal diffusivity of forsterite shows curvature as is the case of Fo89 olivine. This may be due to complex crystal structure of forsterite. Reciprocal thermal diffusivity of corundum shows a linear relation with temperature. However, its gradient does not change with increasing temperature. It is possible that measurement for corundum was failed because thermal diffusivity of corundum is very high Thermal diffusivity of forsterite is 30% larger than that of fo89 olivine. Thermal diffusivity of forsterite increases by 40% over 6 GPa. This pressure dependence is about 40% larger than that of fo89 olivine. Thermal diffusivity of zirconia measured at high pressure is more than 50% larger than expected from the measurement at ambient conditions.
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