Influences of Cu-doped and Sr vacancy on the room magnetoresistance of La0.67Sr0.33−x−yCuxMnO3

Abstract Single-phase perovskite-type manganese oxides La 0.67 Sr 0.33− x − y Cu x MnO 3 ( x =0.10, 0.15, y =0.00, 0.03) polycrystalline samples were synthesized by sol–gel method, where x is the fraction of Cu doped at Sr site, y is the fraction of Sr vacancy. The X-ray diffraction analyses of the samples revealed that all the samples are single-phase with perovskite structure. It is found that the room temperature magnetoresistance (MR) of Cu-doped sample with Sr vacancy is obviously larger than the un-doped La 0.67 Sr 0.33 MnO 3 sample. Under an applied filed of 1.8 T, there is an MR maximum 23% of La 0.67 Sr 0.15 Cu 0.15 MnO 3 at 300 K, whose field susceptivity is about 17%/T below 1.2 T. This field susceptivity around room temperature is highly improved as compared to one of the reported single-phase perovskite structure materials. Therefore, it is important for the potential application of this MR material.