Charge transfer satellites in x-ray spectra of transition metal oxides

Article

关键词: DENSITY-FUNCTIONAL FORMALISM;    ABSORPTION;    PHOTOEMISSION;    SPECTROSCOPY;   

DOI  :  10.1103/PhysRevB.89.085123

来源: SCIE

【 摘 要 】

Strongly correlated materials such as transition metal oxides (TMOs) often exhibit large satellites in their x-ray photoemission (XPS) and x-ray absorption spectra (XAS). These satellites arise largely from localized charge transfer excitations that accompany the sudden creation of a core hole. Here we use a two-step approach to treat such excitations in a localized system embedded in a condensed-matter environment and coupled to a photoelectron. The total XAS is then given by a convolution of an energy-dependent spectral function representing the localized excitations coupled to the photoelectron and the XAS of the extended system. The local system is modeled roughly in terms of a simplified three-level model, leading to a double-pole approximation for the spectral function that represents dynamically weighted contributions from the dominant neutral and charge transfer excitations. This method is implemented using a resolvent approach, with potentials, radial wave functions, and matrix elements from the real-space Green's function code FEFF9, and parameters fitted to XPS experiments. Representative calculations for several TMOs are found to be in reasonable agreement with experiment and with other calculations.

【 授权许可】

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