Effect of thermomagnetic treatment on magnetoresistive properties of trilayer thin films based on FexNi100-x and Cu

We investigated magnetoresistive properties of as-deposited and annealed in magnetic field at different temperatures F/N/F trilayer films based on ferromagnetic FexNi100-x (F-layer) and nonmagnetic Cu (N-layer). The results demonstrate that spin-dependent scattering is realized both in as-deposited and annealed at 400 K trilayer films within the range of thicknesses dF = 15-40 nm and dN = 6-15 nm and at the Ni concentration in magnetic layers cNi ≤ 90 wt %. The annealing at 550 K leads to the decrease of isotropic magnetoresistance value and to the appearance of anisotropy in thin films at the cNi ≥ 50 wt %. It was found that the maximum value of isotropic magnetoresistance has been observed for as-deposited Fe50Ni50(30 nm)/Cu(6 nm)/Fe50Ni50(30 nm)/S thin film at room temperature. The value of isotropic magnetoresistance increases in 1.3-2.2 times with the decline of the measurement temperature from 293 to 120 К depending on components concentration in magnetic layers.