Low field magnetoresistance observed in polycrystalline La0.67Ca0.33Mn1−xO3 sintered at low temperature

Magnetic and electrical transport properties are reported in the La2/3Ca1/3Mn1−xO3 (x = 0–0.10) samples, which are prepared by the sol–gel method followed sintering treatment at 900 °C. Experimental results show, with the increase of x, enhanced extrinsic MR and weakened intrinsic MR effects are observed. Meanwhile, grain size of the samples decreases.