| Project/Area Number |
06640436
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | YOKOHAMA NATIONAL UNIVERSITY |
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Principal Investigator |
YAMAMOTO Ikuo Yokohama National Univ.Faculty of Edu. Associate Prof., 教育学部, 助教授 (70126332)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRASAKI Ryoen Yokohama National Univ.Faculty of Edu. Research Associate, 教育学部, 助手 (90251751)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Elastic Constant / Phase Transition / Stress Effect / Nonlinearity / Perovskite |
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| Research Abstract |
Single crystals of perovskite-type crystal CsPbCl_3 were grown by the modified Stockbarger method. Two cubic samples of about 1 cm^3 were obtained in the present study. Ultrasonic wave velocities of CsPbCl_3 have been measured above the cubic-tetragonal phase trnsition temperature under hydrostatic pressure by the pulse-echo overlap method. Ultrasonic waves of the longitudinal or the transverse mode were generated by quartz transducers of fundamental frequency of 10 MHz.
The combinations of third-order elastic constants C_<111>+2C_<112>'C_<111>-C_<123> and C_<144>+2C_<166> were deduced from pressure derivatives of the sound velocity over the temperature interval 47-100ﾟC.Critical anomalies were found in the temperature dependence of C_<111>+2C_<112> and C_<111>-C_<123>. It has been revealed that the order-parameter fluctuation is responsible for the observed anomaly in the third-order elastic constants .
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