Investigation of Mn 3d derived states in La0.2Sr0.8MnO3

We investigate the Mn 3d derived states in La0.2Sr0.8MnO3 to understand the temperature dependent spectral weight transfer observed in the valence band spectra. Towards this, we have used DFT and DFT+U calculations and x-ray and Mn 3p to 3d resonant photoemission spectroscopic techniques. Our results show that the calculation gives better representation of the experimental valence band spectra for on site Coulomb interaction energy U = 5 eV. The room temperature resonant photoemission technique reveal that the valence band feature similar to 2 eV is of mainly 3d(n) L character (L is the ligand hole formed by ligand to metal charge transfer) and the feature similar to 5 eV is predominantly of O 2p character. As the sample enters the low temperature tetragonal and insulating phase, the Mn 3d character of feature similar to 2 eV increases and of feature similar to 5 eV, it decreases.