Antiferromagnetic coupling across nonmagnetic transition-metal films alloyed with ferromagnetic elements

Interlayer exchange coupling (IEC) has been incorporated into almost all magnetic thin-film devices in the form of synthetic antiferromagnets, yet how such coupling is affected by the mixing of magnetic atoms into the nonmagnetic spacer layer is often overlooked. The authors show that antiferromagnetic IEC can be achieved and enhanced by spacer layers containing over 60 at.% of magnetic atoms, leading to huge antiferromagnetic bilinear coupling strength in multilayers deposited by magnetron sputtering. The magnetic atoms in these spacers exhibit a large magnetic moment, highlighting not only the importance of free electrons but also the role of magnetic moments in governing IEC.