Formation of granular-like structure of Ag/Co multilayers by excimer laser irradiation

Abstract

The electron beam deposited Ag/Co multilayers (MLs) showing the giant magnetoresistance (GMR) were thermally processed by XeCl excimer laser irradiation at the fluences between 0.1 and 0.25 J/cm 2 with 1–200 pulses. An increase of the GMR ratio from 7.5 to 15% at 4.2 K was observed for ML with Ag layers composed of randomly oriented Ag grains at lower laser fluences when the ML was not yet melted. The magnetization M(T) curves of the irradiated samples indicate the presence of granular like component, while the anisotropy of GMR due to layering persists. For Ag/Co ML with coherent structure the effect of irradiation on GMR was minor.