Structural, microstructural, transport, and magnetotransport properties of nanostructured La_0.7Sr_0.3MnO₃ manganites synthesized by coprecipitation

The structural, transport, and magnetotransport properties of single-phase, homogeneous nanostructured La_0.7Sr_0.3MnO₃ (LSMO) manganites synthesized by the coprecipitation route were investigated and the effect of sintering temperature on the microstructure of LSMO compounds was studied. A strong dependence of transport and magnetotransport behavior on the microstructure and nature of grain boundaries has been observed in the single-phase LSMO sintered at various temperatures. High-field magnetoresistance (HFMR) at room temperature is found to increase [13% (LS6) to 25% (LS9)] while low temperature (5 K) magnetoresistance decreases [75% (LS6) to 46% (LS9)] under 9 T field with increase in sintering temperature, which has been attributed to the spin-polarized tunneling and spin-dependent scattering of charge carriers.