外磁场下单离子各向异性海森堡铁磁体的低温磁性质(英文)  

The low-temperature magnetic properties of the Heisenberg ferromagnet with single-ion anisotropy under an external magnetic field

作　　者：吴悠[1] 陈渊[1] 

机构地区：[1]广州大学物理与电子工程学院,广东广州510006

出　　处：《广州大学学报（自然科学版）》2011年第3期18-26,共9页Journal of Guangzhou University:Natural Science Edition

摘　　要：文章运用自旋波理论研究了在外磁场下有单离子各向异性的一维海森堡铁磁体的低温磁性质．通过霍斯坦因一普利马科夫变换得到近似的哈密顿量．详细讨论了磁化强度、磁化率、内能、比热等随温度、各向异性参数和外磁场的变化情况．推导出内能u（t）和比热cm（T）随温度的变化规律u（t）～ta与Cm（T）～tβ，并得出指数a，β与单离子各向异性参数以及外磁场的关系．文章的结果与采用其他理论以及蒙特卡罗模拟所得到的结果相符合．The low-temperature magnetic properties of one-dimensional Heisenberg ferromagnets with single-ion anisotropy in a magnetic field are investigated via the spin wave theory. In this paper, we get the approximate Hamiltonian by means of Holstein-Primakoff transformation. The magnetization, susceptibility, internal energy and specific heat as function of temperature, the anisotropy as well as the applied field are discussed in detail. The internal energy U（T） and specific heat Cm （T） are found to have the power-law behaviors, U（T） - T^a and Cm （T） - Tβ. The exponents a and β are found to depend on the anisotropy D and the external magnetic field h. Good agreement with available theoretical data and Monte Carlo simulations is found.

关 键 词：自旋波理论 海森堡模型 单离子各向异性 

分 类 号：O482.525[理学—固体物理]