Interlayer exchange coupling of antiferromagnetic NiO layers through Cu spacer

The interlayer exchange coupling (IEC) of two antiferromagnetic (AF) NiO layers separated by the nonmagnetic (NM) spacer layer is observed by investigating exchange bias effect in the structure of ferromagnetic (FM)/AF/NM/AF. The IEC shows an oscillatory behavior with a period of about 1.1 nm as the spacer layer thickness increases. The oscillation amplitude and phase also depend on the NiO layer thickness. A qualitative explanation of the experimental results is provided by the RKKY-like IEC between the AF uncompensated spins at the AF/NM interfaces rather than AF itself.