Magneto-optical anisotropy study of Fe n /Au n superlattices
Magneto-optical anisotropy study of Fe n /Au n superlattices
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Fe n /Au n 超晶格的磁光各向异性研究
DOI：
10.1103/physrevb.62.13731
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发表时间：
2000
影响因子：
3.7
通讯作者：
J. Korecki
中科院分区：
文献类型：
--
作者：
L. Uba;S. Uba;V. Antonov;A. Yaresko;T. Ślęzak;J. Korecki
本文对分子束外延制备的一系列Fe_n/Au_n超晶格的大磁光各向异性(MOA)进行了进一步的实验和理论研究，这些Fe_n/Au_n超晶格具有n=1，2，3个(001)取向的Fe和Au原子面。在0.8-5.8 eV的光子能量范围内，根据磁光极化和纵向饱和复克尔角的测量和椭圆偏振光谱测量的光学数据，确定了光学电导张量的非对角分量相对于磁化方向变化的各向异性。在密度泛函理论的局域自旋密度近似下进行的能带结构计算很好地再现了观测到的各向异性的大小，随n的增加而减小，以及它与能量的关系。计算结果表明，大MOA的微观成因是Au位上的强自旋轨道耦合和Fe位上的大交换分裂通过界面电子态的Au d-Fe d杂化相互作用的结果。通过从头算模拟替代无序和界面粗糙度的影响，研究了金属氧化物避雷器对界面结构的高灵敏度。结果表明，当考虑界面粗糙度影响时，计算结果与实验结果吻合较好。根据第一原理计算了d轨道力矩的取向各向异性，并在考虑d轨道对称性的基础上进行了分析。讨论了轨道矩各向异性与MOA的关系。
Extended experimental and theoretical study of the observed large magneto-optical anisotropy (MOA) is presented for a series of Fe n/Au n superlattices prepared by molecular beam epitaxy with n= 1, 2, 3 of Fe and Au atomic planes of (001) orientation. The anisotropy of the off-diagonal component of the optical conductivity tensor with respect to the change of the magnetization direction is determined in the photon energy range 0.8–5.8 eV from the measurements of the magneto-optical polar and longitudinal saturated complex Kerr angles and the optical data measured by the spectroscopic ellipsometry. The magnitude of the observed anisotropy, decreasing with the increase of n, and its energy dependence are well reproduced by the band structure calculations performed within the local spin-density approximation to the density functional theory. The results of the calculations show that the microscopic origin of the large MOA is the interplay of the strong spin-orbit coupling on Au sites and the large exchange splitting on Fe sites via Au d-Fe d hybridization of the electronic states at the interfaces. The high sensitivity of the MOA to the interface structure is studied by ab initio modeling of the effects of substitutional disorder and the roughness at the interfaces. It is shown that a good agreement with the experiment is obtained when the interface roughness effect is taken into account. The orientation anisotropy of the d orbital moment is calculated from the first principles and analyzed on the basis of d orbital symmetry consideration. The relationship between the orbital moment anisotropy and the MOA is discussed.