Spin, Charge, and Orbital Ordering in the B-Site Diluted Manganates La2-xSrxGaMnO6

Oxidation of the ferromagnetic B-site diluted manganese(III) perovskite La 2 GaMnO 6 is investigated by synthesis of the La 2 - x Sr x GaMnO 6 series. At the x = 0.3 composition, which corresponds to diamagnetic element substitution at the B-site of metallic La 0.7 Sr 0.3 MnO 3, the Mn III and Mn IV valences order in real space at low temperature with an unusual lamellar motif. Orbital ordering at the Mn III centers in this array maintains ferromagnetism and enhances the static coherent Jahn−Teller distortion over that found for the pure Mn III end-member, facilitating e g electron hopping in the insulating state. Further oxidation to x = 0.5 completely suppresses the charge and orbital ordering, leading to glassy rather than long-range ordered magnetism.