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 $t_\textrm{Cu}=1.4,$ 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 $t_\textrm{Cu}$ 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 $t_\textrm{Cu}$.