| Project/Area Number |
14550016
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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 |
Applied materials science/Crystal engineering
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| Research Institution | Ritsumeikan University |
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Principal Investigator |
YOSHIMURA Yukio Ritsumeikan Univ., Fac Science and Engineering, Professor, 理工学部, 教授 (10066699)
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| Co-Investigator(Kenkyū-buntansha) |
TOZAKI Kenichi Chiba University, Department of Physics, Faculty of Education, 教育学部, 教授 (30102031)
KOJIMA Akira The Uniyersity of Shiga Prefecture, Department of Material Science, 工学部, 助教授 (00205379)
IWASAKI Hiroshi Ritsumeikan Univ., Fac Science and Engineering, Professor, 理工学部, 教授 (50005857)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | mK-Stabilized Cell / Simultaneous measurements of heat flux and dielectrics / X-ray diffraction / Measurements of displacement / BaTiO_3 single crystal / BaTiO_3単結晶 / CsPbCl_3単結晶 / SrTiO_3単結晶 / Milli-Kelvin-温度制御セル / 超音波共鳴実験 / X線回析実験 / 自発分極の測定 / BaTiO_3結晶 / CsPbBr_3結晶 |
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| Research Abstract |
The good fruit of this year was obtained from the results for both researches of the physical properties and structural studies on three phase transitions of BaTiO3 (high temp. phase-Room temp. phase-Low temp. phase-Most low temp. phase). They made clear the nature of the phase transition mechanism of each phase transition. Single crystals used in this study were grown by top-seeded solution growth method and the crystals were not accomplished poling. It was cleared that each phase transition has different transition mechanism by the measurements of dielectric constant, displacement current, dilatometric measurements, and resonant ultrasonic spectroscopy simultaneous with endothermic or exothermic heat measurements. The result of the resonant ultrasonic spectroscopy, especially, showed that resonant spectra for both the room temperature and the low temperature phases are rather complex compare with the both the high temperature and the most low temperature phases. This result suggested that the crystal structures of the both the room temperature and the low temperature phases are complex compare with those of the high temperature and the most low temperature phases. On the other hand, the organization of this research studies on the physical property of the crystal and on the structural study by X-ray diffraction, independently. The results on the structural study showed that the crystal structure changes by the phase transitions as follow; cubic system-hybrid structure of tetragonal and monoclinic 1 systems-hybrid structure of orthorhombic 1 and monocliic 2 systems-orthorhombic 2. The result is important to explain the obtained physical properties and well agrees with the results expected from the resonant ultrasonic spectroscopy study.
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