铌锰锆钛酸铅铁电陶瓷电滞回线的温度和频率响应

研究了Pb［(Zr052Ti048)095(Mn1/3Nb2/3)005］O3 (PMnN_PZT) 铁电陶瓷电滞回线的温度和频率响应，结果显示在高频和室温条件下测试铁电特性时，电滞回线呈现“束腰”形状，而不是通常所看到的方形回线 . 在低频和高温条件下测试时才能观察到正常的方形回线，同时，诸如矫顽场、极化强度、 内偏场这些重要的铁电参数也会随频率和温度发生显著的变化. 剩余极化强度随频率和温度 的大幅增长表明“束腰” 电滞回线有可能是由于缺陷偶极子引起的. 电滞回线形状与温度 和频率存在较强的相关性说明缺陷偶极子存在一特征弛豫时间，缺陷偶极子反转响应速度由 此弛豫时间决定. 关键词： 电滞回线 氧空位 频率响应 温度响应

Frequency and temperature dependence of the hysteresis loop in PMnN-PZT ceramics

The frequency and temperature dependence of the hysteresis loops in Pb［(Zr0 52Ti048)095(Mn1/3Nb2/3)005］O3 (PM nN_PZT) ceramics have been investigated. It has been demonstrated that the polar ization_field hysteresis curves show “pinched" shapes instead of the normal squ are_like P_E loops when tested at room temperature or higher frequency. While at 200℃ or lower frequency, normal square_like loops are observed. In the meantim e, important ferroelectric features such as coercive field, polarization and int ernal bias field are strongly frequency or temperature dependent. High increase of the remnant polarization (Pr) reveals that there may be defect dipo les that induce the unsaturated hysteresis loop. The close relations between the P_E loops and the applied frequencies or temperatures indicate that there exist s a typical relaxation time associated with reorientation of the defect dipoles.