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Piezoelectricity and hetero-structure fluctuations in ferroelectric materials having composition near a morphotropic phase boundary

具有接近同形相界成分的铁电材料的压电和异质结构波动

基本信息

批准号：
13650726
负责人：
KOYAMA Yasumasa
金额：
$ 2.69万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

In Pb(Zr_<1-x>Ti_x)O_3 (PZT), there exist the ferroelectric tetragonal/monoclinic and monoclinic/rhombohedral phase boundaries around x=0.50, where the very high piezoelectric response has been reported. Among these two boundaries, the former is characterized by the nearly vertical boundary called the morphotropic phase boundary (MPB). In order to understand the physical origin of the excellent piezoelectric property found near the MPB, we have investigated the crystallographic features of the PZT samples around x=0.50 mainly by transmission electron microscopy.The preliminary examination by means of X-ray powder diffraction revealed that the x=0.50 and 0.48 sample exhibited the tetragonal to monoclinic transition, while in the x=0.46 sample near the monoclinic/rhombohedral boundary the rhombohedral phase was basically found in the temperature range below room temperature. Based on the preliminary data, the details of the crystallographic features of these samples were examined by in-s … More itu observation using a transmission electron microscope. The observation indicated that in the tetragonal to monoclinic transition the monoclinic regions with a lenticular shape were nucleated at the {110} twin boundary in the tetragonal phase. The characteristic features are that the nucleated regions do not basically exhibit the growth process, and that the transition proceeds by the repeated nucleation of the monoclinic regions. The monoclinic phase after the transition is then characterized by the aggregation of the lenticular domains. In the x=0.48 sample, on the other hand, there is no crystallographic domain structure. Only the tweed-type structure was observed in the whole area of the sample. This suggests that the x=0.46 sample consists of nm-sized regions with the monoclinic symmetry. In other words the rhombohedral symmetry indicating by X-ray diffraction is just on average area. The excellent piezoelectric property is thus understood be directly associated with the tweed-type microstructure consisted of the nm-size monoclinic regions. Less

在Pb(Zr_<1-x>Ti_x)O_3 (PZT)中，在x=0.50附近存在铁电四方/单斜和单斜/菱面体相界，据报道在该处具有非常高的压电响应。在这两个边界中，前者的特征是几乎垂直的边界，称为同形相边界（MPB）。为了了解MPB附近优异压电性能的物理起源，我们主要通过透射电子显微镜研究了x=0.50附近的PZT样品的晶体学特征。通过X射线粉末衍射初步检查发现，x=0.50和0.48样品表现出四方到单斜的转变，而x=0.46样品在x=0.50附近表现出四方到单斜的转变。单斜/菱面体晶界，菱面体相基本上出现在低于室温的温度范围内。根据初步数据，使用透射电子显微镜通过 in-s itu 观察检查了这些样品的晶体学特征的细节。观察表明，在四方相到单斜晶相的转变中，具有透镜形状的单斜晶区域在四方相的{110}孪晶边界处成核。其特征是成核区域基本上不表现出生长过程，并且转变是通过单斜晶区域的重复成核进行的。转变后的单斜晶相的特征是透镜区域的聚集。另一方面，在x=0.48的样品中，不存在晶域结构。在样品的整个区域中仅观察到花呢型结构。这表明 x=0.46 样本由具有单斜对称性的纳米大小区域组成。换句话说，X射线衍射表明的菱面体对称性只是平均面积。因此可以理解，优异的压电性能与由纳米尺寸单斜区域组成的花呢型微结构直接相关。较少的

项目成果

期刊论文数量（22）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Coexistence of ferroelectricity and antiferroelectricity in lead zirconate titanate

DOI：
10.1103/physrevb.70.104105
发表时间：
2004-09-01
期刊：
PHYSICAL REVIEW B
影响因子：
3.7
作者：
Asada, T;Koyama, Y
通讯作者：
Koyama, Y

Features of structural phase transition in La_<1-x>SrFeO_3

La_<1-x>SrFeO_3结构相变特征

DOI：
发表时间：
2003
期刊：
Physica C 392-396
影响因子：
0
作者：
M.Arao;T.Asada;T.Asada;T.Asada;M.Arao et al.;T.Asada et al.;T.Asada et al.;T.Asada et al.;M.Arao;M.Mogi
通讯作者：
M.Mogi

M.Arao, I.Ueno, T.Asada, Y.Koyama: "Crystallographic features in lightly-doped La1-xSrxMnO3"Physica C. in press. (2004)

M.Arao、I.Ueno、T.Asada、Y.Koyama：“轻掺杂 La1-xSrxMnO3 中的晶体学特征”Physica C. 正在出版。