Low-field magnetoresistance in nanosized La0.7Sr0.3MnO3/Pr0.5Sr0.5MnO3 composites

Abstract
Nanosized La0.7Sr0.3MnO3/Pr0.5Sr0.5MnO3 (LSMO1−xPSMOx) ceramic composites are prepared using solid-sate sintering. Their microstructural, electro- and magnetotransport properties are characterized by means of various techniques. It is found that the antiferromagnetic/ferromagnetic coupling between PSMO/LSMO at low temperature and the weak ferromagnetic order of PSMO at high temperature results in enhanced low-field magnetoresistance (LFMR) of the composites. With increasing temperature up to 250 K the observed LFMR decays more slowly than that for pure LSMO and this behavior may be explained by the spin coupling near boundaries between LSMO and PSMO grains.