A novel hysteresis loop and indirect exchange coupling in Co/Pt/Gd/Pt multilayer films

Abstract

We have investigated the magnetization behavior of Co/Pt/Gd/Pt multilayers in order to study the indirect exchange coupling between Co and Gd through Pt. A novel hysteresis loop has been observed for the samples with Pt layer thicknesses larger than 10 Å. This loop is considered to be due to the combined effect of the antiferromagnetic coupling between Co and Gd layers and the large magnetic anisotropy acting on the Co layer magnetization. The magnetization data suggest that the coupling strength oscillates with the Pt layer thickness.