Positive Effect of Giant Magnetoresistance in Magnetically Ordered Three-Layered Films

Using a phenomenological approach (two-current model [1, 2] and the theory of size effects in metals [3, 4]), a qualitative analysis of the inverse effect of the giant magnetoresistance in the magnetically ordered three-layered films (sandwich) that is quantitatively characterized by the magnetoresistance ratio $\delta$ (MRR) is presented. It is shown that in the region of small thickness of the covering magnetic layer compared to the thickness of the basic metal layer and the non-magnetic interlayer, the conductor MRR increases, while in the opposite region of the covering magnetic layer thickness, the opposite trend is observed, namely, the value of $\delta$ decreases. If the covering magnetic metal layer thickness coincides with the total thickness of the basic magnetic layer and the non-magnetic interlayer, the MRR reaches its maximum value due to the absence of the shunting effect.