X-ray emission and photoelectron spectra of Pr0.5Sr0.5MnO3

The results of measurements of x-ray photoelectron (XPS), x-ray emission (X ES), and x-ray absorption spectra and local spin-density approximation band structure (LSDA) calculations of Pr0.5Sr0.5MnO3 are resented. The excitati on energy dependence of Mn L-2,L-3 and O K alpha x-ray emission spectra of Pr0.5Sr0.5MnO3 is measured using tunable synchrotron radiation. The XES mea surements yielded no photon energy dependence for the O K alpha spectra, bu t the Mn L-2,L-3 spectra yielded inelastic scattering losses of 2 and 6 eV, corresponding to features in the structure of the occupied part of the val ence band. Comparing XPS and XES measurements with LSDA band-structure calc ulations, one concludes that the electronic structure of the compound consi sts mainly of Mn 3d and O 2p states. States of 3d character localized at th e Mn site predominate near the top of the valence band (VB). Some differenc es in the Mn 3d distribution in this part of the XPS valence band and Mn L- 3 XES with d symmetry due to spin-selection rules that govern the Mn L-3 XE S. In addition, the Mn 3d states distribution is hybridized with the O 2p p art of the VB. Mn L-3 XES spectra were determined relative to the Fermi ene rgy by assuming normal x-ray emission begins from the lowest level of the p (5)d(n+1)L intermediate state (which is the Mn 2p ionizatation threshold). From the local spin-density approximation, the orbital character of the Mn 3d electrons can be assigned eg symmetry at the top of the valence band T-2 g in the central part of the VB, and equal contributions of e(g) and T-2g s tates at the bottom of the valence band. [S0163-1829(99)00620-7].