Giant Magnetoresistive Effect in Magnetically Ordered Asymmetric Sandwiches Based on Co and Fe

Abstract

Using two-point [1], [2] and resistor [3] –[8] models, an analysis of the effect of giant magnetoresistance (GMR) in an asymmetric (the magnetic components of a conductor are made of different ferromagnetic metals or different alloys based on them, or one component is an alloy and the other is a metal) magnetically ordered three-layer film (sandwich) was carried out depending on the change in the thickness of the metal covering magnetic layer dm2 and it was shown that when the approximate equality $d_{m1}\cong d_{m2}(d_{m1}$- thickness of the base magnetic layer, $d_{n}-$ thickness of the non-magnetic layer (spacer)) the value of the GMR effect reaches its maximum due to the absence of the shunting effect. Using the sandwich model with an ultrathin interlayer, it is theoretically shown that with the experimentally measured amplitude value of the magnetoresistance ratio (MRR) and knowledge of the asymmetry parameter in spin-polarized electron scattering in the base magnetic layer, it is theoretically possible to calculate the above mentioned asymmetry parameter in the covering magnetic layer.