Charge disproportionation of Mn 3d and O 2p electronic states depending on strength of p-d hybridization in (LaMnO3) 2(SrMnO3)2 superlattices

The charge disproportionation of Mn 3d and O 2p electronic states was investigated in two (LaMnO3)(2) (SrMnO3)(2) superlattices using the resonant x-ray scattering technique. The superlattices show significantly different conductivity even with the same composition. The large modulation of the Mn 3d electronic state was observed in the insulating sample, however the charge disproportionation and magnetic modulation of O 2p were shown in the semiconductive sample. It is suggested that the charge modulation appears in either Mn 3d or O 2p, which is strongly related to strength of the p-d hybridization, which is the main factor determining the electric conductivity in the superlattices.