The Features of the Structural and Magnetic Characteristics of Low-Dimensional Thin-Film Systems Based on Cobalt and Copper

The results of investigation of the structural and magnetic characteristics of Co/Cu/Co thin-film systems obtained by magnetron sputtering on glass substrates are presented. The thickness of the cobalt layer in all samples was 5 nm and the thickness of the copper layer was varied from 0.5 to 4 nm. The saturation field H _S of the studied samples was found to oscillate in magnitude with changes in the copper-layer thickness with a period on the order of 1 nm. The maximum values of H _S are observed for the thin-film systems with t_Cu = 1.4, 2.2, and 3.2 nm. The hysteresis loops measured for these systems in a magnetic field applied along the easy magnetization axis of the samples have a two-stage shape, while for the samples with other values of tCu the hysteresis loops are rectangular. These data are explained by the presence of exchange coupling between the ferromagnetic layers through a copper spacer and its oscillating behavior with changing t_Cu.