PZN基陶瓷超低频介电弛豫的研究

A STUDY OF ULTRA SLOW FREQUENCY DIELECTRIC RELAZATION OF PZN BASED CERAMICS

采用线变零起始电压法，对Ｐｂ（Ｚｎ１／３Ｎｂ２／３）Ｏ３基陶瓷样品在－１５０～１６０℃温度范围内的超慢介电弛豫进行了详细测试；并结合普适型弛豫函数进行了实验数据的有效拟合，实现了介电常数从时域向频域的傅利叶转换，从而得到该样品的超低频（１０－５～１０－１Ｈｚ）介电频谱、温谱．观察到该样品的超低频介电温谱在居里温度点１１０℃附近存在扩散相变温区，并且在相变温区以下表现出明显的弛豫弥散现象、用热刺激电流（ＴＳＣ）得到样品的弛豫激活能Ｅ和本征驰豫时间τ０，并对其弛豫极化机制进行了讨论．

Using the linear voltage ramp method, the ultra slow dielectric relaxation processes of Pb(Zn1/3Nb2/3)O3 based ceramics are carefully measured in the temperature range of -150-160℃. Based on the 'universal' law of dielectric relaxation, it can be realized to fit experi-mental data in time domain and to transform into frequency domain. We can get the dielectric constant spectra of ultra low frequency (10-5-10-1 Hz) at various temperature. It can be es-timated that there is a phase transition temperature region near Tm=110℃. The very strong frequency dispersion of dielectric constant appears in this temperature region. The relaxation activation energy E and the relaxation timeτ0 can be calculated from the thermally stiumulat-ed currant (TSC). The relaxation mechanism is discussed in this paper.