Influence of the thickness of gadolinium layers on the magnetic properties and magnetization reversal processes in low-dimensional Co/Gd/Co systems

Structural and magnetic characteristics and behavior of thin-film Co/Gd/Co systems obtained by ion plasma sputtering in a magnetic field are reported. X-ray studies showed that cobalt layers in all investigated samples have a nanocrystalline structure. The mean roughness $R$a of the surface of the samples does not exceed 0.5 nm and is independent of the Gd layer thickness. The shape of hysteresis loops observed for the Co/Gd/Co system depends of the thickness of the Gd layer, $t_{\operatorname{Gd}}$. The dependence of the saturation field $H_S$ on $t_{\operatorname{Gd}}$ has an oscillatory character. This fact is explained by interaction of the Co layers through the intermediate Gd layer.