Abstract

Considering dipolar interactions between magnetic grains, the effect of cluster size distributions in the magnetoresistance of granular metallic systems is analyzed. In particular, the reduced magnetoresistance and magnetization arc studied for different systems, and it is shown that when a broad grain size distribution is considered, strong effects arc observed. However, the dipole-dipole short range correlation at zero field does not change, when a cluster size distribution is considered. Therefore the reduced magnetoresistance value at zero field is not affected.