Crystallographically amorphous ferrimagnetic alloys: Comparing a localized atomistic spin model with experiments
Crystallographically amorphous ferrimagnetic alloys: Comparing a localized atomistic spin model with experiments
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DOI：
10.1103/physrevb.84.024407
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发表时间：
2011-07-06
影响因子：
3.7
通讯作者：
Kimel, Alexey
中科院分区：
文献类型：
--
作者：
Ostler, Thomas A.;Evans, Richard F. L.;Kimel, Alexey
我们提出了一个计算模型的晶体非晶亚铁磁合金使用随机Landau-Lifshitz-吉尔伯特运动方程的原子自旋和海森堡交换原子自旋哈密顿量。计算了自发平衡磁化强度，并与平均场模型进行了比较。模拟结果表明，GdFeCo使用X-射线磁性圆二色性，以确定个人的亚晶格磁化强度与实验非常吻合。计算的磁化强度的温度依赖性示出的Gd亚晶格的极化导致一个共同的居里温度，与实验数据一致。亚晶格间的交换是超快动力学的一个重要的能量传递通道。
We present a computational model of crystallographically amorphous ferrimagnetic alloys using a stochastic Landau-Lifshitz-Gilbert equation of motion for atomistic spins and an atomistic spin Hamiltonian with Heisenberg exchange. The spontaneous equilibrium magnetization is calculated and a comparison with a mean field model is made. The simulations show excellent agreement with experiments on GdFeCo using x-ray magnetic circular dichroism to determine the individual sublattice magnetizations. The calculated temperature dependence of the magnetization shows a polarization of the Gd sublattice leading to a common Curie temperature, in agreement with the experimental data. The intersublattice exchange is shown to be an important energy transfer channel for ultrafast dynamics.