EFFECT OF MAGNETIC-INTERACTIONS AND MULTIPLE MAGNETIC PHASES ON THE GIANT MAGNETORESISTANCE OF HETEROGENEOUS COBALT-SILVER THIN-FILMS

We have observed magnetic and electrical transport properties in giant magnetoresistive inhomogeneous cobalt-silver films. The material cons ists of two distinct magnetic phases: large clusters which dominate th e magnetization and magnetoresistive processes at room temperature, be tween which cooperative behavior is observed; and small clusters which dominate the magnetization below 10 K, but make only a minor contribu tion to the magnetoresistance. Both the variation of the magnetoresist ance with magnetization in the film and the difference in the magnetor esistance between the zero-field-cooled and field-cycled state are int erpreted by invoking interactions between the active magnetic regions in the sample.