作　　者： ; ;

机构地区： 中山大学物理科学与工程技术学院物理系

出　　处： 《物理学报》 1999年第4期721-728,共8页

摘　　要： 用时域和频域方法研究了（Ｂａ１ｘＳｒｘ）ＴｉＯ３陶瓷的极性相变．类似于单晶的铁电相变所观察到的晶格软化，屏蔽电荷激发和畴运动讯号外，在陶瓷中还出现空间电荷运动的强讯号．空间电荷和电畴属于凝聚态物质的高级结构，它提供慢极化效应．慢效应使频域测量结果不能得到确定值．从统计观点给出高级结构的历史记忆效应对频域测量结果的影响；解释了频域介电常量的倒数在一级结构的转变中发生线性软化，而在高级结构的转变中发生抛物型软化． Abstract By using frequency and time domain dielectric spectroscopy, the polar phase transitions of (Ba 1- x Sr x )TiO 3 ceramics have been studied. Compared with the phase transitions of a ferroelectric crystal, the motion of space charges in ceramic has been obtained as well as lattice softening, excitation of screen charges and motion of ferroelectric domains. Slow effect, which is contributed by ferroelectric domains and space charges, can affect the accurate measurement by frequency domain method. In this paper we describe this influence and explain some experimental results. The reciprocal of frequency domain dielectric constant has a linear softening in the transition of primary structure, but has a parabolic type softening in that of high structure.

关 键 词： 钛酸钡 陶瓷 极性相变 介电谱 时域频域法

领　　域： [电气工程] [一般工业技术] [理学] [理学]