Evidence of local moment formation in Co-based Heusler alloys
Evidence of local moment formation in Co-based Heusler alloys
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DOI：
10.1103/physrevb.78.184438
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发表时间：
2008-11-01
影响因子：
3.7
通讯作者：
Miyazaki, T.
中科院分区：
文献类型：
--
作者：
Telling, N. D.;Keatley, P. S.;Miyazaki, T.
我们使用 X 射线磁圆二向色性和线性二色性相结合的技术，研究了 Co(2)MnZ（其中 Z=Si 或 Al）成分的 Heusler 合金中局部矩的形成。半金属霍斯勒合金中局部矩的存在依赖于少数自旋态的带隙。通过利用 X 射线吸收技术的元素特异性，我们能够探索 Co 和 Mn 原子上矩的局域化程度。在比较 Co2MnSi (CMS) 和 Co2MnAl 薄膜时，我们观察到 Co 矩的局域化存在关键差异，这与 CMS 的 Co 部分态密度中预测的较大少数自旋能隙一致。这些结果为Co少数自旋态在该体系中实现半金属铁磁性中的主导作用提供了重要证据。
We examine the formation of local moments in Heusler alloys of the composition Co(2)MnZ (where Z=Si or Al) using the combined techniques of x-ray magnetic circular and linear dichroism. The existence of local moments in half-metallic Heusler alloys is reliant upon the band gap in the minority-spin states. By utilizing the element-specific nature of x-ray absorption techniques we are able to explore the degree of localization of moments on Co and Mn atoms. We observe a crucial difference in the localization of the Co moment when comparing Co2MnSi (CMS) and Co2MnAl films that is consistent with the predicted larger minority-spin gap in the Co partial density of states for CMS. These results provide important evidence for the dominant role of the Co minority-spin states in realizing half-metallic ferromagnetism in this system.