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

• Published in: Chinese physics B Vol. 19; no. 9; pp. 16 - 24
• Main Author: 朱琛 刘俊明
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.09.2010
• Subjects: Computer simulation; Dielectric relaxation; Dipoles; Dispersions; Ferroelectric materials; Landau理论; Monte Carlo methods; Relaxors; Transition temperature; 介电弛豫; 偶极缺陷; 弛豫铁电体; 模拟集群; 蒙地卡罗; 蒙特卡罗模拟
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/19/9/097702

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.