Studies of remnant magnetoresistance in granular AuCo films

Abstract The observation of remanence effects in the magnetoresistance of a granular Au 0.82 Co 0.18 film is reported. The results obtained, at low temperatures and low magnetic fields, are analyzed on the basis of a simple model for remnant giant magnetoresistance. The comparison with similarly measured magnetization remanence, shows that mainly the small ferromagnetic Co particles, of volume V 3 , account for the giant magnetoresistance (GMR). The novel approach applied here for analyzing the dominant particles size in GMR, could be used for other granular magnetic materials as well.