MEV ION IRRADIATION OF CO CU MULTILAYERS

We examine the effect of MeV ion-beam irradiation on the giant magneto resistance and related interlayer magnetic coupling in sputtered Co/Cu multilayers. At ion doses higher than 10(13)/cm(2), the resistivity o f the multilayers increases noticeably, well beyond that measured for pure copper or cobalt films. This increase in resistivity of the multi layers is tentatively ascribed to ion-beam-induced interface disorder. With increasing dose, the magnetic interlayer coupling passes systema tically from a mainly antiferromagnetic (AF) coupling to a ferromagnet ic one and, in parallel, the giant magnetoresistance (GMR) is progress ively destroyed. A linear relationship between the GMR and the volume fraction of AF coupled regions is observed up to an ion dose of 2 x 10 (14)/cm(2). (C) 1997 American Institute of Physics.