Orbital magnetic moments of Co in multilayers with perpendicular magnetic anisotropy.
Orbital magnetic moments of Co in multilayers with perpendicular magnetic anisotropy.
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DOI：
10.1103/physrevb.49.12888
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发表时间：
1994-05
期刊：
影响因子：
--
通讯作者：
D. Weller;Yanqing Wu;J. Stöhr;M. Samant;B. Hermsmeier;C. Chappert
中科院分区：
文献类型：
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作者：
D. Weller;Yanqing Wu;J. Stöhr;M. Samant;B. Hermsmeier;C. Chappert
利用X射线磁圆二色光谱研究了具有垂直磁各向异性的Co/[ital X]多层（[ital X]=Pd， Pt和Ni）中Co的面外轨道磁矩。在Co/Pd和Co/Pt多层膜中，每个Co原子的轨道[ital d]矩[ital m][子球][sup[垂直]]与单层厚Co膜相比，分别显著提高了（0.15[正负]0.02）[mu][下标B]]和（0.07[正负]0.02）[mu][下标B]]。在Co/Ni的情况下，没有发现相应的增强。这种增强与Ni-3[ital d]、Pd-4[ital d]和Pt-5[ital d]带的自旋轨道耦合参数[xi][sub SO]无关，尽管[ital d]-[ital d]的强烈混合导致了Pd和Pt原子的铁磁矩的存在。然而，观察到面外轨道矩[ital m][sub - orb][sup [vertical]]与每Co体积的本征单轴各向异性常数[ital K][sub - [ital u]，1][sup Co]大致呈线性关系。这一实验发现与最近的[ital ab] [ital initio]和紧密结合能带结构计算相结合，作为Co/Pd和Co/Pt多层中Co的面外轨道矩优先增强的证据。
The out-of-plane orbital magnetic moment of Co in Co/[ital X] multilayers ([ital X]=Pd, Pt, and Ni) with perpendicular magnetic anisotropy has been investigated using x-ray magnetic-circular-dichroism spectroscopy. The orbital [ital d] moment per Co atom, [ital m][sub orb][sup [perpendicular]], is considerably enhanced by (0.15[plus minus]0.02)[mu][sub [ital B]] and (0.07[plus minus]0.02)[mu][sub [ital B]] in Co/Pd and Co/Pt multilayers, respectively, compared with a single thick Co film. No respective enhancement is found in the case of Co/Ni. This enhancement does [ital not] scale with the spin-orbit coupling parameter [xi][sub SO] of Ni-3[ital d], Pd-4[ital d], and Pt-5[ital d] bands despite strong [ital d]-[ital d] mixing which leads to the presence of ferromagnetic moments of Pd and Pt atoms. However, a roughly linear scaling relation of the out-of-plane orbital moment [ital m][sub orb][sup [perpendicular]] with the intrinsic uniaxial anisotropy constant [ital K][sub [ital u],1][sup Co] per Co volume is observed. This experimental finding is interpreted in conjunction with recent [ital ab] [ital initio] and tight-binding band-structure calculations as evidence for a preferential enhancement of the out-of-plane orbital moment of Co in Co/Pd and Co/Pt multilayers.