Giant magnetoresistance in heterogeneous AgCo alloy films

Abstract

Giant magnetoresistance in heterogeneous, sputtered AgCo thin films is reported. The films consist of Co-rich precipitates in an Ag-rich matrix. Δρ/ρ values as high as 55% at 4.2 K and 20% at room temperature are observed. The magnetoresistance is shown to depend on the Co concentration as well as the particle size. Upon annealing, Δρ/ρ first increases, then decreases. Δρ, however, decreases monotonically with annealing.