On the magnetic structure of γ-FeMn alloys
On the magnetic structure of γ-FeMn alloys
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DOI：
10.1063/1.1458922
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发表时间：
2002-05
影响因子：
3.2
通讯作者：
G. M. Stocks;W. Shelton;T. Schulthess;B. Ujfalussy;W. Butler;A. Canning
中科院分区：
文献类型：
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作者：
G. M. Stocks;W. Shelton;T. Schulthess;B. Ujfalussy;W. Butler;A. Canning
合金 γ-FeMn 是面心立方反铁磁体的罕见例子。它已成为磁电子器件中钉扎层研究的原型。在这里，我们报告了基于无序合金大晶胞模型的 γ-FeMn 磁结构的第一原理计算结果。计算基于约束局部矩模型并使用第一原理自旋动力学来获得基态取向构型。与之前的层 KKR-CPA 研究一致，我们发现 3Q 状态是所研究的三个原型结构（1Q、2Q、3Q）中最低的。然而，引入理论以维持特定取向构型的约束场不为零，这表明即使 3Q 结构也不是基态。随后使用第一原理自旋动力学对磁性配置进行优化，产生能量降低 2.5 meV/原子的状态。
The alloy γ-FeMn is a rare example of a fcc antiferromagnet. It has become a prototype for pinning layer studies in magnetoelectronic devices. Here we report the results of first principles calculations of the magnetic structure of γ-FeMn based on large cell models of the disordered alloy. The calculations are based on the constrained local moment model and use of first principles spin dynamics to obtain the ground state orientational configuration. In agreement with previous layer KKR-CPA studies, we find the 3Q-state to be lowest of the three prototype structures studied (1Q,2Q,3Q). However, the constraining fields introduced into the theory to maintain a specific orientational configuration are not zero indicating that even the 3Q-structure is not the ground state. Subsequent optimization of the magnetic configuration using first principles spin dynamics yields a state that is lower in energy by 2.5 meV/atom.