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

Abstract

The results of measurements of x-ray photoelectron (XPS), x-ray emission (XES), and x-ray absorption spectra and local spin-density approximation band structure (LSDA) calculations of Pr0.5Sr0.5MnO3 are resented. The excitation 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 measurements yielded no photon energy dependence for the O K alpha spectra, but 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 valence band. Comparing XPS and XES measurements with LSDA band-structure calculations, one concludes that the electronic structure of the compound consists mainly of Mn 3d and O 2p states. States of 3d character localized at the Mn site predominate near the top of the valence band (VB). Some differences 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 XES. In addition, the Mn 3d states distribution is hybridized with the O 2p part of the VB. Mn L-3 XES spectra were determined relative to the Fermi energy 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-2g in the central part of the VB, and equal contributions of e(g) and T-2g states at the bottom of the valence band. [S0163-1829(99)00620-7].