A review of the innershell photoionization of the 3d transition elements in the region of the 3p ionization (30-70 eV) and of the 2p ionization (400-900 eV) is given. For the 3p ionization the photoelectron spectra can be described by the dominant Coulomb interaction between the 3p hole and 3d valence subshells causing a large exchange splitting between the so-called high-spin and low-spin components and the spin dependence of the sub-sequent Auger decay causing a large broadening of the low-spin components. The 2p photoelectron spectra offer a complex situation due to the different influence of the spin-orbit splitting of the 2p hole, the Coulomb interaction of the 2p hole with the 3d valence subshell and the Coulomb interaction within the 3d valence subshell itself.
P. Zimmermann, P. Zimmermann,
"Innershell photo-ionization of the 3d transition elements", Proc. SPIE 5258, IV Workshop on Atomic and Molecular Physics, (17 November 2003); doi: 10.1117/12.544338; https://doi.org/10.1117/12.544338