X-ray absorption and resonant photoemission studies of Mn doped SrTiO3 epitaxial films

Synchrotron radiation was used to measure X-ray absorption and resonant photoemission of epitaxial Mn doped SrTiO3 film. The spectra together with the modeling revealed that Mn valence state depends on the ions localization in the film and on the annealing temperature. The XAS spectra can be fitted by the composition of Mn3+ and Mn2+. Surface region was richer in trivalent Mn, while deeper layers and the film annealed in UHV at 630 °C exhibited mostly divalent Mn ions. Partial density of Mn 3d electronic states derived from the resonant photoemission showed a significant contribution to the in-gap states.