一种具有铁磁与反铁磁相互作用Ising模型的热力学性质  

THERMODYNAMICAL BEHAVIOR OF THE ISING MODEL WITH FERROMAGNETIC AND ANTI- FERROMAGNETIC INTERACTIONS

作　　者：黄东[1] 翁永刚[1] 

机构地区：[1]河南广播电视大学理工系,郑州大学物理系,河南省自然科学基金资助的课题。

出　　处：《物理学报》1994年第7期1172-1176,共5页Acta Physica Sinica

摘　　要：对最近邻自旋间具有反铁磁相互作用Ｊ＿ｓ，相隔偶数个自旋间又具有指数型长程铁磁相互作用Ｊ＿１的一维Ｉｓｉｎｇ模型，利用积分方程的方法得出内能和比热的解析表达式。在Ｊ＿１＝１，Ｊ＿ｓ分别为０．０５，０．１和０．３的条件下，作出零场时的内能和比热随温度参量变化的图形，并指出其相变临界点。在Ｊ＿１＝１，Ｊ＿ｓ＝０．１的条件下，作出外磁场变化对内能和比热的影响图。鉴于系统在低温、零场或弱场以及较弱的反铁磁作用下出现双解，推论该模型在拍应条件下还存在一种亚稳态。sing the integral equation method,we have got theanalytic expressions of theinternal energy and specific heat for the one-dimensional Ising model with nearest。neighbour antiferromagnetic repulsion Js and infinitely long-range exponential(Kac-Helfand-type)ferromagnetic attraction J_1 acting only on even-numbered neighbours。Under the conditions of J_1=1 and Js being 0.05,0.1 and 0.3 respectively,we liavedrawn the curves of the internal energy and specific heat varying with temperature inzero external magnetic field,and pointed out its critical phase transition point.Und-erthe conditions of J_1=1,Js=0.1,we have drawn the curves of influence of theexternal magnetic field upon the internal energy and specific heat.Because there exi。st double solutions for the system under low temperatures, zero or weak externalmagnetic field and weaker antiferromagnetic interactions,it is inferred that thereshould exist another quasi-stable state of the model under the given conditions。

关 键 词：伊辛模型 铁磁性 反铁磁性 热力学 

分 类 号：O482.5[理学—固体物理]