硅掺杂PMS-PZT材料的晶界行为对畴结构和压电性能的影响

Domain Morphology and Piezoelectric Properties of Si-doped PMS-PZT Piezoelectric Ceramics Affected by Grain Boundary Action

运用XRD、TEM、EDS等实验手段,研究了Si离子掺杂对PMS-PZT材料的相结构、微观结构以及电畴形貌的影响.XRD测试结果表明,所有材料都显示钙钛矿结构,四方度(c/a)随着掺杂量的增加而增大.TEM研究结果表明,随着Si离子掺杂量的增加,电畴的形貌由鱼刺型过渡到微米级的带状畴,最后转变为波浪状的电畴.EDS表明在材料的晶界处含有纳米级的SiO2和PbSiO3,并且发现单斜晶系的孪晶ZrO2在晶界附近析出.本文对孪晶ZrO2的析出及其析出量随着硅离子含量增加而增加的原因作了解释,最后对材料压电性能的降低进行了探讨.

The microstructure, phase properties and domain morphology of Si-doped PMS-PZT ceramics were investigated by using X-ray diffraction (XRD), transmission electron microscope (TEM) and energy dispersive spectrometry (EDS). XRD results indicate that all specimens show perovskite structure and tetragonal distortion (c/a) increases as the dopant content increases. TEM results show that domain morphology evolves from the normal herringbone domain to micron-sized lenticular shape domain structure, and finally changes to ' wavy ' pattern as SiO2 content changes from 0 similar to 1wt%. The nano-scale secondary phases Of SiO2 and PbSiO3 were observed on the grain boundary, and the twinned ZrO2 was found surrounded by PMS-PZT perovskite phase. The mechanism of the appearance of twinned ZrO2 and its content increase with the increase of Si concentration were discussed.