粗大晶粒PZT陶瓷中电畴的结构

Investigation of the ferroelectric domain of PZT ceramic

应用扫描力显微镜(SFM)的压电响应模式观测未经抛光处理的PZT陶瓷片的电畴结构,用纵向压电响应信号和侧向压电响应信号获得PZT陶瓷材料三维电畴结构。结果表明,将样品晶粒的微形貌与SFM的纵向和侧向压电响应信号相结合,能准确表征粗大晶粒样品的三维电畴结构。用SFM可观测表面不经任何处理的陶瓷样品的电畴,不会引入表面应力等影响因素,能得到样品的原生畴结构。对原生畴结构的观察表明,对于受应力较大的晶粒,成畴的主要原因是降低应变能,而受应力较小的晶粒成畴的主要原因是降低退极化能。

Scanning force microscope (SFM) was applied to observe the ferroelectric domains of PZT ceramic with rough surface. Domains in-plane and out-plane were detected using piezoresponse in longitudinal and transverse directions, respectively. The influence of the big grains on the imaging of the ceramic surface was investigated. A method in which exact 3D domain structure of coarse sample can be obtained was suggested. Different from other methods of observing ferroelectric domains, SFM was adapted to the ferroelectric bulk ceramic that had never been polished. The as-grown domain structure was observed. The observation of domain in PZT ceramic confirms that the main reason for the formation of domain in grains with less stress is the decreasing of depolarization energy, while that in grains with bigger stress is the decreasing of strain energy.