Magnetic properties and microstructural characterization of granular Ag-Fe films

Abstract

The magnetization and magnetotransport properties of Ag-Fe granular films have been investigated with hysteresis cycles and DC resistivity measurements under applied magnetic fields up to 1.5 T. These samples, grown by RF sputtering, comprised iron clusters embedded in silver matrix, whose grain size dependence on the sputtering power has been extracted from the magnetization curves. The behaviour of the magnetoresistance as a function of the sputtering power, displaying a maximum around 60 W, is discussed in the frame of two competing magnetic scattering mechanisms. Besides, the capability of Joule heating to modify the microstructure of these granular samples is shown in the magnetoresistance results. These results confirm the development of enhanced magnetic correlations amongst the enlarged iron clusters. © 2002 Elsevier Science B.V. All rights reserved.