基于二维Ising模型及Monte-Carlo模拟的锰氧化物Griffiths相研究  

Study on the Griffiths Phase in manganites based on the Monte-Carlo simulation of 2-D Ising model

作　　者：石将建[1] 张红光[1] 葛晓鹏[1] 赵亮[1] 陆梓幸[1] 李旗[1] 

机构地区：[1]东南大学物理系,江苏南京211189

出　　处：《化工时刊》2011年第9期12-16,共5页Chemical Industry Times

基　　金：东南大学大学生创新性实验计划(No.10102001);国家大学生创新性实验计划(No.101028622)

摘　　要：在对锰氧化物磁性质实验研究的基础上,利用二维Ising模型及Monte-Carlo方法模拟存在非Ising自旋掺杂系统的磁性质。模拟结果表明,对非Ising自旋系统进行部分掺杂将导致系统的磁性质背离居里外斯定律,出现Griffiths相,通过对非Ising格点紧邻格点自旋大小的统计平均值进行计算,分析了非Ising自旋影响系统磁性质的微观机制。为解决模拟结果与实验结果的差异,通过对铁磁团簇的比例提出假设,在模拟的基础上计算系统磁性质,获得了与实验一致的结果。On the basis of 2 - D Ising model and Monte - Carlo simulation and the experimental results, in this paper, we have studied the magnetic properties of a typical system which is doped with non - Ising spins. The results of simulation show that the existence of non - Ling spins could make the magnetic properties of the system deviate from the Curie - Weiss law and make the Griffiths Phase appear. By calculating the average spin value of an Ising spin which is next to a non - Ising spin, the microscopic mechanism of the influence caused by non - Ising spin is given in this paper. To diminish the difference between the simulation and experimental results, an amendment is put forward which takes the ferromagnetic cluster into consideration and an agreement with the experimental results is achieved.

关 键 词：锰氧化物Griffiths相二维Ising模型Monte—Carlo模拟铁磁团簇 

分 类 号：O614.711[理学—无机化学]