Formation of granular-like structure of Ag Co multilayers by excimer laserirradiation

The electron beam deposited Ag/Co multilayers (MLs) showing the giant magne toresistance (GMR) were thermally processed by XeCl excimer laser irradiati on at the fluences between 0.1 and 0.25 J/cm(2) with 1-200 pulses. An incre ase of the GMR ratio from 7.5 to 15% at 4.2 K was observed for ML with Ag l ayers 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 anisotr opy of GMR due to layering persists. For Ag/Co ML with coherent structure t he effect of irradiation on GMR was minor. (C) 1999 Elsevier Science S.A. A ll rights reserved.