Soft x-ray absorption spectroscopy study of Mo-rich SrMn1−xMoxO3(x⩾0.5)

Electronic structures of perovskite oxides of SrMn${}_{1\ensuremath{-}x}$Mo${}_{x}$O${}_{3}$ in the Mo-rich regime ($x\ensuremath{\geqslant}0.5$) have been investigated by employing soft x-ray absorption spectroscopy (XAS). Mn $2p$ XAS spectra of SrMn${}_{1\ensuremath{-}x}$Mo${}_{x}$O${}_{3}$ indicate that the valence states of Mn ions are divalent and that they remain nearly unchanged for $x\ensuremath{\geqslant}0.5$. On the other hand, the Mo $3p$ XAS spectra of SrMn${}_{1\ensuremath{-}x}$Mo${}_{x}$O${}_{3}$ show some changes, suggesting that the valence states of Mo ions decrease with increasing $x$ for $x\ensuremath{\geqslant}0.5$. These conclusions are supported by the unoccupied Mn $3d$ and Mo $4d$ states, observed experimentally in the O $1s$ XAS spectra of SrMn${}_{1\ensuremath{-}x}$Mo${}_{x}$O${}_{3}$.