W(110)基底上的铁纳米岛初始自发磁化态的微磁学模拟

Micromagnetic simulations of the initial spontaneous magnetic states of nanoscale Fe islands on W(110) substrates

用微磁学模拟研究W(110)基底上铁纳米岛的初始自发磁化态的磁畴结构,确定了不规则形状、椭圆形和矩形岛中不同磁畴态之间的各向异性常数的临界点,得到了纳米岛的磁化态作为各向异性常数和厚度函数的完整相图,相图中存在一较宽的过渡区,把双畴态与涡旋态和菱形态分开,过渡区两侧的边界是不确定的.计算结果表明,初始自发磁化态的磁畴结构主要由各向异性及岛的厚度决定,而且岛的边沿形状对涡旋态和菱形态的磁畴结构有重要影响.准确的铁纳米岛的各向异性常数仍有待于进一步确定.

The initial spontaneous magnetic domains in nanoscale Fe islands on W （110） substrates are studied numerically with micromagnetic simulations. The critical anisotropies separating different domain states for irregular, elliptic and rectangular shape islands are determined precisely. A full phase diagram of magnetic domain states as a function of anisotropy and thickness is obtained, in which there is a wide transition zone separating two domain states from vortex or diamond domains, and the boundaries on two sides of the transition zone are indefinite. The calculated results indicate that the initial spontaneous magnetic domains are determined mainly by anisotropies and thicknesses, and rim shapes have significant influences on vortex and diamond domain configurations. Further study is needed to determine the exact anisotropies of nanoscale Fe islands.