Magnetoresistance in Cu-Co granular films and Co/Cu/Co sandwiches

Abstract

Cu1-xCOx granular films with x equals 19, 27, 43, and 45 achieved by sputtering with different argon gas pressure are studied by the magnetic and magnetoresistance measurement. With the increase of the sputter argon gas pressure P, the remanence and coercive force increases, but the MR ratio has a maximum value around P equals 1.5 Pa, confirming that a proper size of Co grains and a suitable concentration are required for the large MR. And for Co/Cu/Co sandwiches, we found there was an MR ration oscillation as Cu layer thickness was varied.