Perpendicular giant magnetoresistances of Ag/Co multilayers

Measurements at 4.2K of the magnetoresistance (MR) measured with the current perpendicular to the layer planes (CPP) of equal and unequal thickness Ag/Co magnetic multilayers that display giant MR measured with the current in the layer planes (CIP) are presented. For Ag layer thicknesses from 2-60 nm, and cobalt thicknesses from 6-15 nm, the CPP MR extends up to approx 50% and ranges from three times to more than ten times as large as the CIP MR for the same samples.