Explanation of Giant Magnetoresistance Effect in Magnetic Co/Cu/Co Sandwiches

Using a two-current model [1], [2] and the theory of dimensional effects [3], [4], a qualitative analysis of the giant magnetoresistance effect in a three-layer magnetically ordered film (sandwich), which is quantitatively characterized by a magnetoresistance ratio (MRR) $\delta$, was presented. It was shown that in the region of small thickness of the magnetic covering layer, in comparison with the thickness of the basic metal layer and the non-magnetic layer, the MRR of the conductor increased, while in the opposite region of the thickness of the magnetic covering layer, the opposite trend is observed, namely, the value of $\delta$ decreased. In the case when the thickness of the magnetic covering layer of the metal coincided with the total thickness of the basic magnetic layer and the non-magnetic layer, the MRR reached its maximum value due to the absence of a shunt effect.