Electrical and magnetic properties of non-stoichiometric (La0.8Sr0.2)1−xMnO3 perovskites

The structure, transport and magnetic properties of (La0.8Sr0.2)1−xMnO3 (0≤x  ≤0.30) polycrystalline perovskite manganites have been investigated. For all the samples the Curie temperatures, TcTc, remain nearly unchanged (329±3 K). Resistivity versus temperature curves for the samples show a double-peak behavior. A significant magnetoresistance (MR) effect and different temperature dependences of the MR ratios of the samples are observed. The shapes of the MR–TT curves of the samples can be adjusted by changing xx. For the x=0.30x=0.30 sample, a nearly constant MR ratio of (9.5±0.5)% is obtained over the temperature range from 205 to 328 K.