铌镁酸铅弛豫型铁电陶瓷的介电老化行为研究

Study on the Dielectric Aging of Pb(Mg_(1/3)Nb_(2/3))O_3 Relaxor Ferroelectric Ceramics

通过典型弛豫型铁电陶瓷铌镁酸铅介电老化行为的研究，发现高温区的Ｄｅｂｙｅ 型弛豫过程与介电老化现象存在有机联系，指出复合钙钛矿弛豫型铁电体的结构缺陷特征对其介电老化起着重要作用。介电极化行为与老化行为对比分析和恒温经时老化研究表明，结构缺陷上的局域化电子和空穴对铁电微畴畴壁“钉扎”效应产生弛豫型铁电体介电老化行为的快过程。

The aging effect on temperature and time dependence of dielectric permittivity and loss angle tangent was examined for 0.9Pb(Mg 1/3 Nb 2/3 )O 3-0.1PbTiO 3 and 0.1% MnO 2-0.95Pb(Mg 1/3 Nb 2/3 )O 3-0.05PbTiO 3 relaxor ferroelectric ceramics.There are clearly Debye dielectric relaxation process in higher temperature range for the latter composition,but in absence of the former.It is stressed that the stabilization of ferroelectric domain structure is due to the presence of defects in perovskites.Compared with dielectric poling behavior of the compositions,a pin effect was introduced to analyze the dielectric aging.The localized electrons and holes around defects form the pinning center for ferroelectric microdomain walls,which may be a key reason of fast dielectric aging of perovskite relaxor ferroelectrics.