PTC型BaTiO_3陶瓷的孪晶和孪晶界

TWIN AND TWIN BOUNDARY IN PTC BaTiO_3 CERAMICS

用透射电镜和高分辨电镜观察研究了PTC型BaTiO_3陶瓷的孪晶和孪晶界结构,并提出了可能的{111}孪晶及孪晶界的原子结构模型。结果表明,{111}孪晶形成氧八面体共面的共格倾斜孪晶界,在孪晶界处可能存在一定量的A空位且原子密度要低于孪晶体内。同时还发现两种其它特征的孪晶现象。

The twin and twin boundary in PTC BaTiO_3 ceramics were studied by TEM and HREM. An atomic structure model of {111} plane twin boundary was constructed according to HREM study result, the results indicate that the {111} twin boundary is characterized by the octahedra with sharing face and is in the form of coherency tilt twin boundary which has a density less than that in twin crystal. Another two kinds of twin with specific features were also found.