Intrinsic deviations in fluorescence yield detected x-ray absorption spectroscopy: the case of the transition metal L2,3 edges
Intrinsic deviations in fluorescence yield detected x-ray absorption spectroscopy: the case of the transition metal L2,3 edges
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DOI：
10.1088/0953-8984/24/45/452201
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发表时间：
2012-11-14
影响因子：
2.7
通讯作者：
de Groot, Frank M. F.
中科院分区：
文献类型：
--
作者：
Kurian, Reshmi;Kunnus, Kristjan;de Groot, Frank M. F.
从积分的2 p3 d共振x射线发射谱计算了3d过渡金属离子的荧光产额（FY）检测的x射线吸收谱（XAS）。将得到的FY-XAS谱与相应于吸收截面的正常XAS谱进行了比较，发现两者之间存在明显的偏差，这表明FY-XAS谱与XAS谱一致的假设是错误的。特别是对于早期过渡金属系统的FY-XAS和XAS之间的差异是大的，由于非弹性衰减通道从选定的X射线吸收的最终状态的开放。理论计算表明，FY探测与XAS探测的差别在退偏几何条件下最大。对Fe ~（2+）、Co ~（2+）和Ni ~（2+）体系的氧化物和配位化合物进行了计算，并与实验光谱进行了比较。在XAS和磁性圆二色性实验的总和规则的影响进行了讨论。
Fluorescence yield (FY) detected x-ray absorption spectra (XAS) of 3d transition metal ions are calculated from the integrated 2p3d resonant x-ray emission spectra. The resulting FY-XAS spectra are compared with the normal XAS spectra corresponding to the absorption cross section and significant deviations between the two spectra are found. This implies that the assumption that the FY-XAS spectrum identifies with the XAS spectrum is disproved. Especially for the early transition metal systems the differences between the FY-XAS and XAS are large, due to the opening of inelastic decay channels from selected x-ray absorption final states. The theoretical calculations show that the difference between FY detection and XAS is largest for the detection in depolarized geometry. The calculations are compared with experimental spectra for oxides and coordination compounds for Fe2+, Co2+ and Ni2+ systems. The implications for the sum rules in XAS and magnetic circular dichroism experiments are discussed.