Influence of sintering temperature on low-field spin-polarized tunneling magnetoresistance of La0.7Ca0.3MnO3

In this study we report the effect of sintering temperature on the low field magnetoresistance (LFMR) of La0,7Ca0,3MnO3 manganite synthesized through sol-gel technique. The La0,7Ca0,3MnO3 has been sintered at 600˚C, 700˚C, 800˚C, 900˚C and 1200˚C. The crystallite as well as particle size also show strong dependence on the sintering temperature. While the ferromagnetic – paramagnetic (FM-PM) transition temperature remains almost constant, the metal – insulation transition temperature drop gradual and the low field magnetoresistance (LFMR) increase with a decrease in grain size.