Investigation of perpendicular magnetic anisotropy in Pd/Co2FeSi/MgO structures with evaluations of magnetic property, crystal structure, and elemental mapping
Investigation of perpendicular magnetic anisotropy in Pd/Co2FeSi/MgO structures with evaluations of magnetic property, crystal structure, and elemental mapping
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DOI：
10.1016/j.jmmm.2022.169796
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发表时间：
2022-08
影响因子：
2.7
通讯作者：
E. Matsushita;Y. Takamura;S. Nakagawa
中科院分区：
文献类型：
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作者：
E. Matsushita;Y. Takamura;S. Nakagawa
作者研究了多层全Heusler Co2 FeSi（CFS）合金、MgO和Pd中垂直磁各向异性（PMA）的起源。CFS厚度对磁性能的依赖性表明，即使在CFS厚度为10 nm的样品中，CFS层的体磁各向异性也有助于PMA。当CFS = 1.8 nm和0.7 nm时，各向异性常数急剧增加。晶体结构分析表明，当CFS层厚度大于1.8 nm时，CFS层存在面外拉伸应变，通过磁致伸缩效应产生体磁各向异性。通过扫描透射电子显微镜的元素映射显示，约2 nm厚的Pd存在于CFS/MgO界面处。作者认为当CFS的厚度小于2nm时，整个CFS层都可以包含Pd。这种Pd可能导致CFS厚度小于2nm的样品的体各向异性，因为一些Pd合金和Pd/Co和Pd/Fe多层膜具有大的体磁各向异性。
The authors investigated origins of perpendicular magnetic anisotropy (PMA) in a multilayer of full-Heusler Co2FeSi (CFS) alloys, MgO, and Pd. The CFS thickness dependence of the magnetic properties indicated that the bulk magnetic anisotropy of the CFS layers also contributed to the PMA even in the samples where the CFS thicknesstCFSwas 10 nm. The anisotropy constant was drastically increased attCFS= 1.8 nm, and 0.7 nm. The crystal structure analysis indicated that CFS layers had the tensile strain for out-of-plane when the thickness was thicker than 1.8 nm, which can induce the bulk magnetic anisotropy via the magnetostrictive effect. The elemental mapping by a scanning transmission electron microscope revealed that approximately 2 nm thick Pd existed at the CFS/MgO interface. The authors considered the whole CFS layers could contain Pd when the thickness of CFS was less than 2 nm. This Pd might cause the bulk anisotropy of the samples with the CFS thickness below 2 nm since some Pd alloys and Pd/Co and Pd/Fe multilayers have large bulk magnetic anisotropy.