Transition elements exhibit strong correlations and configuration interactions between core and valence excited states, which give rise to different excitations inside materials. Nickel exhibits satellite features in its emission and absorption spectra. Effects of such transitions on the optical constants of nickel have not been reported earlier and the available database of Henke et al. does not represent such fine features. In this study, the optical behaviour of ion beam sputter deposited Ni thin film near the L_2,3‐edge region is investigated using reflection spectroscopy techniques, and distinct signatures of various transitions are observed. The soft X‐ray reflectivity measurements in the 500–1500 eV photon energy region are performed using the soft X‐ray reflectivity beamline at the Indus‐2 synchrotron radiation source. Kramers–Kronig analysis of the measured reflectivity data exhibit features corresponding to spin orbital splitting and satellite transitions in the real and imaginary part of the refractive index (refraction and absorption spectra). Details of fine features observed in the optical spectra are discussed. To the best of our knowledge, this is the first study reporting fine features in the measured optical spectra of Ni near its L_2,3‐edge region.

中文翻译：

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自旋轨道分裂和卫星跃迁对其L2,3吸收边缘区域附近的镍软X射线光学性能的影响

过渡元素在核心和价态激发态之间表现出很强的相关性和构型相互作用，从而引起材料内部的不同激发。镍的发射光谱和吸收光谱显示出卫星特征。这种转变对镍的光学常数的影响尚未有较早的报道，Henke等人的可用数据库也没有报道。并不代表这么好的功能。在这项研究中，离子束溅射沉积的L _2,3附近的Ni薄膜的光学行为使用反射光谱技术研究边缘区域，并观察到各种跃迁的不同特征。使用Indus-2同步加速器辐射源的软X射线反射率光束线在500–1500 eV光子能量区域中进行软X射线反射率测量。所测反射率数据的Kramers-Kronig分析显示出与折射率的实部和虚部（折射和吸收光谱）中的自旋轨道分裂和卫星跃迁相对应的特征。讨论了在光谱中观察到的精细特征的细节。据我们所知，这是第一项报道在Ni的L _2,3边缘区域附近的实测光谱中具有精细特征的研究。