STUDY ON THE DIELECTRIC PROPERTY AND PHASE TRANSITION OF PEROVSKITE STRUCTURE TYPE RELAXOR MATERIALS

钙钛矿结构型弛豫材料的介电性能及相变研究

• 批准号: 03650615
• 负责人: TSURUMI Takaaki
• 金额: $ 1.22万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650615/
• 关键词: FERROELECTRICS; PIEZOELECTRICS; PEROVSKITE; PHASE TRANSITION; PZT; 誘電分散; ペロブスカイト化合物; 誘電体; リラクサ-

This study was carried out in order to investigate the relationship between electrical properties and crystal structures of lead based perovskite materials and make the mechanism of diffused phase transition of them clear.At first, effect of Mn addition to lead zirconate titanate (PZT) on electromechanical properties was studied from viewpoints of crystal and electronic structures. Then, it was confirmed that Mn addition made PZT a piezoelectrics with both high coupling factor and low mechanical loss. It was clarified that the high coupling factor of Mn-doped PZT was originated from the decrease in the axis ratio c/a caused by Mn addition and that the low mechanical loss was caused by the existence of oxygen defects introduced with Mn3+ and/or Mn2+ for charge compensation.Secondary, we studied the mechanism of the diffused phase transition of lead magnesium niobium oxide (PMN). The following facts were confirmed. 1)PMN shows ferroelectricity under -40C and the degree of the ferroelectricity increases with the decrease in temperature. 2)The crystal structure of PMN keeps cubic one down to -100C. 3)PMN shows large dielectric dispersion around 0C and there are ion hoppings near 0C. From these results, we supposed the following model related to the diffuse phase transition of PMN. PMN has ferroelectric micro domain which size is smaller than coherent length of X-ray and the region of it become large as temperature decreasing. It thermally fluctuates near the room temperature and the fluctuation relates to the ion hoppings and the relaxation frequency of them decreases with the decrease in temperature. Around Tc, PMN shows a large dielectric dispersion under 1000kHz because the relaxation frequency is found near there. As a result, it was clarified that the diffuse phase transition of PMN was a phenomenon originated from the increase in the region of the ferroelectric micro domain and the freezing of the micro domain fluctuation with the decrease in temperature.

为了研究铅基钙钛矿材料的电学性能与晶体结构之间的关系，明确扩散相变的机理，本文首先从晶体结构和电子结构的角度研究了锰对锆钛酸铅（PZT）机电性能的影响。然后，证实了Mn的添加使PZT成为一种既具有高耦合因子又具有低机械损耗的压电体。研究表明，Mn掺杂PZT的高耦合系数是由于Mn的加入降低了PZT的轴比c/a，而低机械损耗是由于Mn ~（3+）和Mn ~（2+）引入了氧缺陷进行电荷补偿。以下事实得到证实。1)PMN在-40 ℃以下表现出铁电性，且铁电性随温度的降低而增强。2)PMN的晶体结构在-100 ℃时仍保持立方结构。3)PMN在0 C附近表现出大的介电色散，并且在0 C附近存在离子跳跃。根据这些结果，我们推测了与PMN的扩散相变有关的以下模型。PMN具有铁电微畴，其尺寸小于X射线的相干长度，并且随着温度的降低，其范围变大。它在室温附近有热涨落，涨落与离子跳跃有关，离子跳跃的弛豫频率随温度的降低而降低。在Tc附近，PMN在1000 kHz下表现出较大的介电色散，因为弛豫频率在那里附近。结果表明，PMN的扩散相变是由于铁电微畴区域的增大和微畴波动随温度降低而冻结引起的现象。

项目成果

神谷 利夫,鈴木 利昌,鶴見 敬章,大門 正機: "Effects of Manganese Addition on Piezoelectric Properties of Pb(Zro._5Tio._5)O_3" Jpn.J.Appl.Phys. 31. 3058-3060 (1992)

Toshio Kamiya、Toshimasa Suzuki、Takaaki Tsurumi、Masaki Daimon：“添加锰对 Pb(Zro._5Tio._5)O_3 压电性能的影响”Jpn.J.Appl.Phys. 31. 3058-3060 (1992)

T.Kamiya, T.Suzuki, T.Tsurumi, M.Daimon: "Effects of Manganese Addition on Piezoelectric Properties of Pb(Zr_<0.5>Ti_<0.5>)O_3" Jpn.J.Appl.Phys.31, 9B. 3058 (1992)

T.Kamiya、T.Suzuki、T.Tsurumi、M.Daimon：“添加锰对 Pb(Zr_<0.5>Ti_<0.5>)O_3 压电性能的影响”Jpn.J.Appl.Phys.31, 9B。

Toshio Kamiya,Toshimasa Suzuki,Takaaki Tsurumi Masaki Daimon: "Effects of Mangarese Addition on Piezoelectric Properties of Pb(Zr_<0.5> Ti_<0.5>)O_3" JPn.J.Appl.Phys.31. 3058-3060 (1992)

Toshio Kamiya、Toshimasa Suzuki、Takaaki Tsurumi Masaki Daimon：“添加 Mangarese 对 Pb(Zr_<0.5> Ti_<0.5>)O_3 压电性能的影响”JPn.J.Appl.Phys.31。