Monte Carlo simulation on dielectric relaxation and dipole cluster state in relaxor ferroelectrics  

作　　者：朱琛 刘俊明 

机构地区：[1]Laboratory of Solid State Microstructures,Nanjing University [2]International Center for Materials Physics,Chinese Academy of Sciences

出　　处：《Chinese Physics B》2010年第9期16-24,共9页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.50832002 and 10874035);the National Basic Research Program of China (Grant No.2009CB623303)

摘　　要：The Ginzburg-Landau theory on ferroelectrics with random field induced by dipole defects is studied by using Monte Carlo simulation, in order to investigate the dipole configuration and the dielectric relaxation of relaxor ferro-electrics. With the increase of random field, the dipole configuration evolves from the long-range ferroelectric order into the coexistence of short-range dipole-clusters and less polarized matrix. The dipole-cluster phase above the transition temperature and superparaelectric fluctuations far below this temperature are identified for the relaxor ferroelectrics. We investigate the frequency dispersion and the time-domain spectrum of the dielectric relaxation, demonstrating the Vogel-Fulcher relationship and the multi-peaked time-domain distribution of the dielectric relaxation.The Ginzburg-Landau theory on ferroelectrics with random field induced by dipole defects is studied by using Monte Carlo simulation, in order to investigate the dipole configuration and the dielectric relaxation of relaxor ferro-electrics. With the increase of random field, the dipole configuration evolves from the long-range ferroelectric order into the coexistence of short-range dipole-clusters and less polarized matrix. The dipole-cluster phase above the transition temperature and superparaelectric fluctuations far below this temperature are identified for the relaxor ferroelectrics. We investigate the frequency dispersion and the time-domain spectrum of the dielectric relaxation, demonstrating the Vogel-Fulcher relationship and the multi-peaked time-domain distribution of the dielectric relaxation.

关 键 词：relaxor ferroelectrics domain structure relaxation spectrum Ginzburg-Landau theory 

分 类 号：TM221[一般工业技术—材料科学与工程]