Abstract:
The ceramic composites La$_{0.7}$Sr$_{0.3}$MnO$_3$/Sb$_2$O$_3$ with different weight ratios of the components have been synthesized. Their magnetoresistive properties have been studied in weak magnetic fields. The values of negative isotropic magnetoresistance of the 90% La$_{0.7}$Sr$_{0.3}$MnO$_3$/10% Sb$_2$O$_3$ composites at room temperature are found to be 1.2% and 14% for 0.25 and 20 kOe, respectively. The observed increase in magnetoresistance with an increase in the field has specific features of the relaxation process.