Many-Electron Effects in Co 3s X-Ray Photoelectron Spectra of Diamagnetic ScCoO3 and Paramagnetic BiCoO3 Cobaltites

A new method based on the solution of the Dyson equation in the basis of atomic wavefunctions has been developed to quantitatively describe the influence of the dynamic effect on the structure of X-ray photoelectron spectra of 3s electrons of 3d elements. The method has been tested for BiCoO3 and ScCoO3 cobaltites containing Co3+ cations in high-spin (S = 2) and low-spin (S = 0) states, respectively. The calculations are in quantitative agreement with the structure of observed spectra of 3s electrons. For the diamagnetic cation Co3+, a significant influence of the dynamic effect on the energy of the unsplit 3s line of ScCoO3 has been demonstrated for the first time both experimentally and theoretically and its energy position has been calculated. For the paramagnetic cation Co3+, the results obtained have been generalized to the case of transition 3d metals with an arbitrary number of unpaired electrons. It also has been shown that, if the 3d shell is filled by half or more, the dynamic effect affects only the energy position of the low-spin component, which reduces splitting by a factor of about 3 (from 13.4 to 4.7 eV in the case of BiCoO3).