超薄磁膜磁特性的Heisenberg 模型分析.PDF

26 1 Vol. 26, No . 1 2005 3 Journal of Hebei University of Science and T ec nology Mar . 2005 : 1008-1542( 2005) 01-0015- 06 Heisenberg 任世伟, 孙敬伟 ( 河北科技大学理学院, 河北石家庄 050018) : 应用Monte Carlo 方法, 研究了交换相互作用表面各向异性和长 偶极相互作用共同作 用下的超薄磁膜的磁特性通过计算不同参数下系统的温度效应, 分析了各种相互作用对系统状 态的不同影响在此基础上, 通过分析自旋垂直分量绝对值等序参量的变化特征, 发现在适当参数 时, 系统自旋通过温度效应可越过垂直取向和平面取向间的势垒, 从而发生从垂直磁化向面内磁化 的转变 : Heisenberg 模型; 取向相变; Monte Carlo 方法 : O4825 : A Analysis of t e magnetic properties in ultrat in films by Heisenberg model REN S -i w ei, SUN Jing-w ei ( College of Sciences, Hebei University of Science and T ec nology, S ijiaz uang Hebei 050018, C ina) Abstract: In t is paper, by using Mont e Carlo simulations, w e ave studied t e magnetic propert ies of t e ultrat in films w it t e surface anisotropy, long- ranged dipole interaction and s ort-ranged exc ange interact ion. T roug t e calculation of t e temperature effect in different parameters, t e different influences of various interactions on t e be aviors of t e system are t eoretically analyzed. On t e basis of t ese analyses, by studying t e features of t e absolute values of t e perpendicular com- ponent of t e spin, it is found t at t e reorientat ion transition from an out-of-plane p ase t o an in-plane p ase can occur w en t e spins get across t e potential barrier betw een t e out-of plane and t e in-plane ordered state t roug t e effects of t e tem- perature under t e suitable parameters. Key words: Heisenberg model; reorientat ion transition; Monte Carlo simulation , , [ 1] , , , 1~ 10 , , 10 D. P. Pappas [ 2] , , , , , , : R. Allenspac : 2004-04-06; : 2004- 09-22; : : ( E2004000290) ; (