A new method on the study of phase transition "Phase Transition seeing by Milli-Kelvin Stabilized cell" Development and Application

研究相变的新方法“毫开尔文稳定池观察相变”的开发与应用

• 批准号: 14550016
• 负责人: YOSHIMURA Yukio
• 金额: $ 2.3万
• 依托单位: Ritsumeikan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550016/
• 关键词: 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; 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

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.

今年的良好果实是从对Batio3的三个相变（高温相位室温度。相位阶段最低温度。相位阶段最低温度阶段）的三个相变的研究结果中获得的。他们明确了每个相变的相变机理的性质。这项研究中使用的单晶是通过顶种子溶液生长法生长的，并且晶体没有完成。可以清楚地看到，通过测量介电常数，位移电流，扩张测量值以及共振的超声光谱与吸热或放热热测量，通过测量介质常数，位移电流，扩张测量值以及共振的超声光谱。尤其是谐振超声光谱的结果表明，室温和低温相的谐振光谱与高温和最低温度相相比相当复杂。该结果表明，室温和低温相的晶体结构都与高温和最低温度相的晶体结构相比。另一方面，这项研究的组织对晶体的物理特性以及X射线衍射的结构研究进行了独立。结构研究的结果表明，晶体结构随相变而变化如下。四方和单斜肌1系统杂交结构的立方系统杂交结构，正骨1和单元2个系统 - 正晶2系统 - 杂种结构。结果对于解释获得的物理特性和良好的结果与共振超声光谱研究的结果相吻合很重要。