Electronic Structure of Doped La-Mn-O Perovskites

The electronic structure of the doped perovskite manganese oxides La$\text{}_{1-x}$Sr$\text{}_{x}$MnO$\text{}_{3}$ and La$\text{}_{1-x}$Ba$\text{}_{x}$MnO$\text{}_{3}$ has been investigated by X-ray photoelectron and X-ray emission spectroscopy. By comparing the O K$\text{}_{α}$ and Mn L$\text{}_{α}$ X-ray emission spectra with the valence band X-ray photoelectron spectra we could localize the Mn 3d and O 2p states into the valence band. Our data are compared with previous band structure calculations. The value of the Mn 3s splitting does not change with Sr-doping in the concentration region from x=0.0 till x=0.3. This shows that the doping holes have mainly oxygen p character. The large value of the splitting indicates that the 3d electrons are in the high-spin state.