Multiple Scattering Approach to the Theory of Angular Dependence of K-edge X-Ray Magnetic Circular Dichroism
Multiple Scattering Approach to the Theory of Angular Dependence of K-edge X-Ray Magnetic Circular Dichroism
复制标题
K边X射线磁圆二色性角相关理论的多重散射方法
DOI：
10.1143/jjap.41.2005
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发表时间：
2002
影响因子：
1.5
通讯作者：
S. Nagamatsu
中科院分区：
文献类型：
--
作者：
T. Fujikawa;S. Nagamatsu
基于半相对论短程有序完全多重散射理论，采用2-旋量形式描述自旋轨道耦合和自旋相关交换散射，讨论了角相关K边X射线磁性圆二色性（XMCD）谱.到目前为止，大多数理论方法都局限于圆偏振X射线传播与磁场方向一致的最简单情况。在这里，我们使用上述理论方法讨论更一般的情况。除了众所周知的角度依赖性，我们有一个新的术语与不同的角度依赖性。这个术语可以提供关于X射线吸收原子周围的磁性原子的对称性降低的有用信息。这种效应预计将在实验中观察到。我们分别讨论了原子、单次和多次散射的XMCD谱，特别是对它们的各向异性特征进行了详细的研究。我们发现在相邻原子的自旋轨道耦合起着次要的作用，然而，自旋相关的交换散射在XMCD分析中起着重要的作用。
We discuss the angular-dependent K-edge X-ray magnetic circular dichroism (XMCD) spectra based on the semi-relativistic short-range order full multiple-scattering theory, where 2-spinor formalism is used to describe spin-orbit coupling and spin-dependent exchange scattering. So far, most of the theoretical approaches have been limited to the simplest case where the circularly polarized X-ray propagation coincides with the direction of the magnetic field. Here we discuss more general cases using the above theoretical approaches. In addition to the well-known angular dependence, we have a new term with different angular dependence. This term can provide useful information on the symmetry lowering of magnetic atoms around the X-ray absorbing atom. This effect is expected to be experimentally observed. We separately discuss atomic, single and full multiple-scattering XMCD spectra, in particular, the anisotropic features of them are studied in detail. We found the spin-orbit coupling at neighboring atoms plays a minor role; however, spin-dependent exchange scatterings plays an important role in XMCD analyses.