MAGNETORESISTANCE IN (FE-CO) AG FILMS

The structural and magnetotransport properties of (Fe(y)Col(1-y))(100- x)Ag-x films were studied as a function of composition. Giant magnetor esistance (GMR) values were measured in these granular films, with the best GMR obtained for the composition (Fe0.33Co0.67)(27)Ag-73, with v alues of 29% at 30 K and 11.7% at 300 K. XRD and TEM results have show n a fee crystal structure with a relatively homogeneous microstructure . Magnetic data for the samples with the best GMR indicate a superpara magnetic behavior. The narrow peak in thermomagnetic data and low bloc king temperature suggest a small and uniform size distribution of magn etic granules. A summary of the electrical transport properties is pre sented, in relation to the structural, microstructural, and magnetic p roperties.