Observation of giant magnetoresistance in Ag-Ni-Fe alloy films

Abstract

We report the observation of a large magnetoresistance in as-deposited co-sputtered Ag-Ni-Fe films. The size of the magnetoresistance has been measured as a function of the film composition. Measurement of the samples’ hysteresis indicates that smaller Ag concentrations result in regions of the films becoming ferromagnetically coupled while greater concentrations result in the formation of a superparamagnetic state. Crystallographic evidence obtained using x-ray diffraction shows the samples to have the crystal structure of a contracted Ag lattice possibly caused by the inclusion of Ni and Fe.