GIANT MAGNETORESISTANCE AND MICROSTRUCTURES IN COAG GRANULAR FILMS FABRICATED USING ION-BEAM COSPUTTERING TECHNIQUE

The correlation between the GMR effect and the microstructures in ion- beam co-sputtered CoAg granular films was systematically studied. The highest magnetoresistance was observed in Co22Ag78 samples. It is sens itive to the annealing treatment and to;the size of the cobalt granule s. The microstructures of the sample were studied by a variety of stru ctural techniques. HREM provides a clear two-dimensional image of as-d eposited Co22Ag78 samples. Real-time observation of TEM together with FMR indicates that the shapes and sizes of cobalt granules evolve prim arily in plane during the annealing process.