Magnetoresistive Properties of Multilayer Film Systems Based on Permalloy and Silver

In this paper, the experimental investigation focuses on the magnetoresistive properties of nanosized film systems. Their structure changes from layered to granular due to transition from bilayer FM/NM (FM is a ferromagnetic material, NM is a nonmagnetic material) to [FM/NM]n multilayer film at a constant total thickness of samples. As ferromagnetic and nonmagnetic materials were chosen permalloy Ni80Fe20 (Py) and Ag, respectively. It was demonstrated that the shape of the field dependences of magnetoresistance depends on the number of bilayer Py/Ag. For as-deposited [Py/Ag]n/S at n = 8, 16, the transition from the antiferromagnetic ordering of magnetic moments to ferromagnetic one occurs under an external magnetic field. As a result, the resistivity of the samples reduced, and the giant magnetoresistive effect was realized. The increase of the number of bilayers repeats from 2 to 16 at the unchanged total thickness of the system leads to the growth of the magnetoresistance from 0.1 % to 0.35 %. During annealing up to 600 K, the magnetoresistive effect is reduced, but it does not disappear completely