The dielectric and ferroelectric behaviors of relaxor ferroelectrics over the ferroelectric transition range are simulated using Monte Carlo simulation. The simulation is based on the Ginzburg-Landau ferroelectric model lattice in which a random distribution of two types of defects (dopants) which will suppress and enhance the local polarization, respectively, is assumed. The simulation reveals an evolution of the ferroelectric transitions from a normal first-order mode toward a diffusive mode, with increasing defect concentration. The simulated lattice configuration shows the microdipole ordered clusters embedded in the matrix of paraelectric phase over a wide range of temperature, a characteristic of relaxor ferroelectrics. The relaxor-like behaviors are confirmed by the lattice free energy, dielectric susceptibility, and ferroelectric relaxation evaluated as a function of the defect concentration. Finally, we present a qualitative comparison of our simulated results with the simulation based on the coarse-grain model [C. C. Su, B. Vugmeister, and A. G. Khachaturyan, J. Appl. Phys. 90, 6345 (2001)].
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机译：使用蒙特卡洛模拟法模拟了弛豫铁电体在铁电跃迁范围内的介电和铁电行为。该模拟基于Ginzburg-Landau铁电模型晶格，其中假定两种类型的缺陷（掺杂剂）分别抑制和增强局部极化的随机分布。仿真结果表明，随着缺陷浓度的增加，铁电从正常的一阶模态向扩散模态转变。模拟的晶格配置显示了在宽温度范围内嵌入顺电相矩阵中的微偶极有序簇，这是弛豫铁电体的特征。由晶格自由能，介电敏感性和铁电弛豫作为缺陷浓度的函数来确认弛豫样行为。最后，我们将模拟结果与基于粗粒度模型的模拟进行定性比较。 C. Su，B。Vugmeister和A.G. Khachaturyan，J.Appl。物理90，6345（2001）]。
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