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

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.

今年的良好成果是BaTiO3的三个相变（高温相-室温相-低温相-最低温相）的物理性质研究和结构研究的成果。他们明确了各个相变的相变机制的本质。本研究中使用的单晶是通过顶晶溶液生长方法生长的，并且晶体没有完成极化。通过与吸热或放热测量同时进行的介电常数、位移电流、膨胀测量和共振超声光谱测量，明确了每种相变具有不同的转变机制。特别是共振超声光谱的结果表明，与高温和最低温度相相比，室温和低温相的共振谱都相当复杂。这一结果表明，与高温相和最低温度相相比，室温相和低温相的晶体结构都很复杂。另一方面，本研究的组织独立地研究了晶体的物理性质和X射线衍射的结构研究。结构研究结果表明，晶体结构因相变而发生如下变化；立方晶系-四方晶系和单斜晶系1的混合结构-斜方晶系1和单斜晶系2的混合结构-斜方晶系2。该结果对于解释所获得的物理性质具有重要意义，并且与共振超声光谱研究的预期结果非常吻合。

项目成果

A.Kojima, Y.Yoshimura, H.Iwasaki, K.Tozaki: ""temperature : Its Measurement and Control in Science and Industry"American Institute of Physics. (2003)

A.Kojima、Y.Yoshimura、H.Iwasaki、K.Tozaki：“温度：科学和工业中的测量和控制”美国物理研究所。(2003)

A.Kojima, Y.Nishibori, Y.Maeda, N.Inoue, Y.Yoshimura, N.Tokunaga, H.Iwasaki, K.Tozaki: "Heat Flow and X-ray Diffraction Study on the Phase Transitions in CsPbcl_3"Ferroelectrics. Vol.284. 113-120 (2003)

A.Kojima、Y.Nishibori、Y.Maeda、N.Inoue、Y.Yoshimura、N.Tokunaga、H.Iwasaki、K.Tozaki：“CsPbcl_3 相变的热流和 X 射线衍射研究”铁电体。

A.Kojima, H.Sasou, K.Tozaki, Y.Yoshimura, N.Tokunaga, H.Iwasaki: "Precise Simultaneous Measurements of Thermal, Electrical and Acoustic Properties-New Feature of the 403 K Phase Transition in BaTiO_3"proceedings of The 15th Symposium on Thermophysical Pro

A.Kojima、H.Sasou、K.Tozaki、Y.Yoshimura、N.Tokunaga、H.Iwasaki：“热学、电学和声学性能的精确同步测量 - BaTiO_3 中 403 K 相变的新特征”会议论文集

A.Kojima, Y.Yoshimura, H.Sasou, N.Tokunaga, H.Iwasaki, K.Tozaki: "New Finding of Phase Transition Feature in BaTiO_3"proceedings of The 10^<th> Eufopean Meeting on Ferroelectricity, Aug. 3-8, 2003 Cambridge, UK. (2003)

A.Kojima、Y.Yoshimura、H.Sasou、N.Tokunaga、H.Iwasaki、K.Tozaki：“BaTiO_3 相变特征的新发现”第 10 届欧洲铁电会议会议记录，8 月 3 日

A.Kojima, Y.Kawakatsu, H.Sasou, Y.Yoshimura H.Iwasaki, K.Tozaki: "Novel Feature of the Phase Transitions in. BaTiO_3 Revealed by "inK-Stabilized Cell""Ferroelectrics. Vol.284. 93-106 (2003)

A.Kojima、Y.Kawakatsu、H.Sasou、Y.Yoshimura H.Iwasaki、K.Tozaki：““inK 稳定电池”揭示了 BaTiO_3 中相变的新特征”铁电体。