摘要
采用MonteCarlo方法对由异类自旋组成混合Heisenberg自旋体系进行了数值计算 ,以模拟和预测基于交换耦合模型纳米双相 (硬磁 软磁 )磁性体系的磁性 .区别于以往所报道的那些直接针对硬磁Nd Fe B与软磁纳米α Fe复合磁体的微磁学计算工作 ,着眼于符合Heisenberg模型的两类完全不同的原子自旋集团 (硬磁自旋和软磁自旋 )之间的直接交换耦合作用 ,模拟计算了由这两类自旋组成的复合自旋体系的内禀矫顽力Hc、剩余磁化强度Mr、最大磁能级 (M×H) max等宏观磁性参量随软磁自旋集团的尺度和体积百分比、两类自旋集团之间交换耦合常数以及它们在磁晶各向异性和饱和磁矩差异的变化 .计算工作中全部采用约化量 ,不针对具体某一种磁性材料 。
The magnetism of a dual\|phase magnetic system consisting of both hard and soft magnetic phases in nanometer scale was studied through Monte Carlo numerical simulation to classical discrete Heisenberg model mixed with spin\|clusters of different species.Unlike those previous computations which focused solely on the concrete dual\|phase alloy of Nd\|Fe\|B plus α Fe studied by other investigators on the basis of micro\|magnetism,our current simulation instead concentrates upon the direct exchange coupling among the spin\|clusters of same and different species by introducing,within the Hamiltonian of standard Heisenberg model,both determinant and random anisotropic energy terms which signify hard\|magnetic and soft\|magnetic phases respectively.We disclosed in this paper the dependences of inherent coercivity H c,remanence M r and maximal energy product ( M×H) max upon such key parameters as the size and volume fraction of spin\|clusters,the coupling constant of exchange interaction between dissimilar spin\|clusters, the difference between the anisotropic constants as well as the saturation magnetic moments of hard and soft magnetic phases.It should be noted that all the simulated quantities in this paper were taken in unitless reduced form and therefore the main conclusions of this paper were of universality at least within the range of parameters we investigated here.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第10期2362-2368,共7页
Acta Physica Sinica
基金
广东省自然科学基金 (批准号 :990 2 13 )资助课题~~
