Electronic structure of SrRu_1-xMn_xO₃ studied by photoemission and x-ray absorption spectroscopy

In order to investigate the change in the electronic structure with Mn doping of SrRu_1-x Mn_x O₃ (SRMO), we have performed soft x-ray synchrotron photoemission spectroscopy (PES) and x-ray absorption spectroscopy (XAS). In the soft x-ray PES spectra, the sharp peak structure near the Fermi level (E_F), which was clearly observed in SrRuO₃, was suppressed accompanied with Mn doping in SRMO. In the Mn2p XAS and Mn2p-3d resonant PES spectra, we have confirmed the existence of Mn³⁺ ions with the electron doping to Mn3d e_g states and Mn3d partial density of state never have finite intensity at E_F in SRMO. These results suggest that the metal-insulator transition of SRMO with Mn doping is originated from the charge transfer from the itinerant Ru4d t _2g bands to the localized Mn3d e_g orbitals.