掺杂二维Ising系统的相图研究  

Investigation on the phase diagram of the two-dimensional doped Ising model

作　　者：王兴福[1] 王茂华[1] 马梅[2] 周岚[1] 

机构地区：[1]扬州大学物理科学与技术学院,江苏扬州225002 [2]扬州工业职业技术学院,江苏扬州225127

出　　处：《扬州大学学报（自然科学版）》2007年第2期19-22,共4页Journal of Yangzhou University：Natural Science Edition

基　　金：国家自然科学基金(10347118);江苏省高校自然科学基金(06KJD140133)

摘　　要：用Monte-Carlo模拟方法研究了非磁性掺杂下二维Ising系统的相图.在平面四角点阵上,以晶格Ising模型为框架,在周期性边界条件下详细观测了不同非磁性物质掺杂浓度下系统磁化强度和磁畴生长随温度变化的关系,并根据有限尺寸标度理论得到其相变温度.结果发现:当掺杂浓度较低时,存在铁磁与顺磁间的相变;而掺杂浓度较高时,在仅考虑近邻作用下系统无铁磁相.当考虑次近邻相互作用时,发现相变温度将升高.另外考察了不同掺杂浓度下的自旋密度关联.The phase diagram of two-dimensional doped lsing model with nonmagnetic matter is studied by Monte-Carlo method in this paper. Under different doping concentration, the relation between system magnetization / domain boundary growth and temperature increasing is observed under periodic boundary condition on the plane square lattices, and the phase transition temperature is also obtained with finite scale measure theory. The result shows that there exists phase transition from ferromagnetic state to paramagnetic state when doping concentration is low, and when doping concentration is high, only nearest-neighbor interaction considered, there is no ferromagnetic state. When next-nearest-neighbor interaction is considered, it is found that phase transition temperature is increased. In this paper, the spin density relating of different doping concentration is also studied.

关 键 词：ISING模型 MONTE-CARLO模拟 相图 

分 类 号：O482.51[理学—固体物理] O552.6[理学—物理]