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, T c , 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– T curves of the samples can be adjusted by changing x . For the x = 0.30 sample, a nearly constant MR ratio of (9.5±0.5)% is obtained over the temperature range from 205 to 328 K.