Manipulation of the interlayer exchange coupling in perpendicular magnetized thin films via tunable magnetic-layer and spacer thicknesses

Abstract

In this work, we fabricated interlayer exchange-coupled magnetic thin films with ferromagnetic layers separated by a spacer layer. We investigated the dependencies of the sign and strength of the interlayer exchange coupling (IEC) and magnetic configurations on both the ferromagnetic layer thicknesses and the spacer thickness. The change of sign of the IEC between the ferromagnetic layers can occur for a thickness change of ferromagnetic layers by as small as approximately 0.1 nm. By comparison, a minimum of approximately 0.2 nm spacer thickness change is required for the same transformation. We attribute the ferromagnetic layer thickness dependence of the IEC to changes in thermal magnon excitations and quantum interferences inside ferromagnetic layers that affect interactions between the ferromagnetic layers and the spacer layer. Our experimental results suggest that the IEC modifications via changing the magnetic-layer thickness can be more efficient for magnetic memory and sensing applications.