Pb(Zr_(0-52)Ti_(0-48))O_3陶瓷畴界粘滞运动的介电损耗模拟

SIMULATION OF DIELECTRIC LOSS RELATED WITH THE MOTION OF DOMAIN WALLS

对不同频率下（１ —１０ ｋ Ｈｚ） Ｐｂ（ Ｚｒ０５２ Ｔｉ０４８） Ｏ３ 多晶陶瓷的介电性能的测量表明：在接近铁电相变温度 Ｔｃ 以下存在一介电损耗峰，该峰具有弛豫特征但不满足 Ａｒｒｈｅｎｉｕｓ 关系．这一损耗峰被认为是由于畴界与晶格、缺陷钉扎的互作用引起的．用畴界粘滞运动的动力学方程，考虑陶瓷样品中 Ｔｃ 离散分布的情况，模拟了该介电损耗峰在不同频率下的行为，得到了与实验数据一致的结果．并由拟合参数计算了畴界运动的粘滞系数和缺陷钉扎引起的回复力常量．

The measurement of dielectric susceptibility under various frequencies for Pb(Zr 0 52 Ti 0 48 )O 3(PZT) ceramics shows that there exists a dielectric loss peak below and close to phase transition temperature, which is relaxational characteristic but disagrees with Arrhenius relation. The peak arise from the interaction between domain walls, lattice and pinning defects. In this paper the behavior of the dielectric loss peak of PZT under various frequencies is simulated by using the dynamic equation of viscous motion of domain walls and by considering the Curie temperature dispersion in ceramics as well. The agreement between the simulatied result and experimental data is quite satisfactory. And from the parameters of simulation the viscous coefficient of the motion of domain walls and the recovering force constant of pinning defects are calculated. PACC: 7722G; 7780; 7784