Multiple-scattering theory of x-ray magnetic circular dichroism: Implementation and results for the iron K edge
Multiple-scattering theory of x-ray magnetic circular dichroism: Implementation and results for the iron K edge
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DOI：
10.1103/physrevb.54.7334
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发表时间：
1996-09-01
影响因子：
3.7
通讯作者：
Bennemann, KH
中科院分区：
文献类型：
--
作者：
Brouder, C;Alouani, M;Bennemann, KH
提出了K边x射线吸收光谱中x射线磁圆二色性（XMCD）的多重散射方法。利用Dirac Green函数的展开式解决了由于簇大小和相对论修正引起的收敛问题。费米能量是通过复平面积分来处理的。给出了在整个复平面上求半相对论格林函数的数值方法。我们提出了一种计算bcc铁的K边磁圆二色性的方法，并考虑了核孔效应。在高能量处发现了很好的一致性。分析了XMCD谱在近边缘和远边缘的物理来源。讨论了芯孔的影响、多重散射展开的可能性以及XMCD与态自旋极化密度的关系。用刚性带模型对K边的XMCD进行了简单的解释。
An implementation of the multiple-scattering approach to x-ray magnetic circular dichroism (XMCD) in K edge x-ray absorption spectroscopy is presented. The convergence problems due to the cluster size and the relativistic corrections are solved using an expansion of the Dirac Green function for complex energies up to second order in 1/c. The Fermi energy is dealt with via a complex plane integration. Numerical methods used to obtain the semirelativistic Green function in the whole complex plane are explained. We present a calculation of the magnetic circular dichroism at the K edge of bcc iron including the core hole effect. A good agreement is found at high energy. The physical origins of the XMCD spectrum near the edge and far from the edge are analyzed. The influence of the core hole, the possibility of a multiple-scattering expansion, and the relation of XMCD with the spin polarized density of states are discussed. A simple interpretation of XMCD at the K edge is presented in terms of a rigid-band model.