用TEM研究改性钛酸铅陶瓷电畴的结晶学特性

TEM STUDY ON CRYSTALLOGRAPHY CHARACTERISTIC OF DOMAINS IN Sm AND Mn MODIFIED LEAD TITANATE CERAMICS

用透射电镜（ＴＥＭ）和选区电子衍射（ＳＡＥＤ）技术，研究了Ｓｍ 和Ｍｎ 改性钛酸铅压电陶瓷的电畴的结晶学特性。结果表明，改性ＰｂＴｉＯ３ 压电陶瓷中存在大量的电畴界面，畴界面为｛１０１｝，畴界两侧晶体的ｃ轴夹角取决于晶胞参数（ａ 和ｃ），约为８６．４°，而不是９０°。这种电畴的［１００］晶带选区电子衍射图特征为：［０１１］方向衍射斑点开裂，而［０１１－ ］上衍射斑点重合，不开裂。

The crystallography characteristics of the ferroelectric domains in Sm and Mn modified lead titanate ceramics had been studied by transmission electron microscopy(TEM) and selected area electron diffraction (SAED). Results indicated that there were a lot of ferroelectric domain walls and domain wall planes were {101}. The angle between c axes of the adjacent domains depends on crystal parameters a and c is about 87° but not 90°. Select area electron diffraction patterns of this kind of domains display spot splitting along [011] direction, but spot superposition along [001-] direction. Hereby 90° and 180° domain walls can be identified.