Strong anti-ferromagnetic coupling in /spl tau/MnAl/Co perpendicular magnetic superlattices on GaAs

This paper reports on the structural and magnetic properties of /spl tau/MnAl/Co superlattices epitaxially grown on AlAs/GaAs by Molecular Beam Epitaxy. In /spl tau/MnAl/Co superlattices with Co layer thickness <8 /spl Aring/, a strong antiferromagnetic coupling between the ferromagnetic /spl tau/MnAl and Co layers is found, as well as the presence of a large perpendicular magnetic anisotropy in both constituent layers, resulting in an unusually abrupt spin reversal at high fields. When increasing the Co layer thickness, the shape anisotropy in the Co layers dominates this AF coupling and the constituent layers display different magnetization directions: perpendicular (/spl tau/MnAl) and parallel (Co) to the growth plane.