Mn 3d bands and Y-O hybridization of hexagonal and orthorhombic YMnO thin films.

We report here the O K-edge x-ray absorption spectra of hexagonal and orthorhombic YMnO thin films, aiming at comparing the changes in the Mn 3d bands as well as the role of Y 4d-O 2p hybridization. The experimental results were analyzed using first principles (GGA) band structure calculations. The spectra present clear differences in the Mn 3d bands, which are attributed to changes in the Mn-O coordination and symmetry. A strong Y 4d-O 2p hybridization is observed in both the hexagonal and orthorhombic films, and its possible role on the occurrence of the observed ferroelectricity is discussed.