Aligning spins in antiferromagnetic films using antiferromagnets

We have explored the possibility to orient spins in antiferromagnetic thin films with low magnetocrystalline anisotropy via the exchange coupling to adjacent antiferromagnetic films with high magnetocrystalline anisotropy. We have used MnO as a prototype for a system with negligible single-ion anisotropy. We were able to control its spin direction very effectively by growing it as a film on antiferromagnetic CoO films with different predetermined spin orientations. This result may pave the way for tailoring antiferromagnets with low magnetocrystalline anistropy for applications in exchange bias systems. Very detailed information concerning the exchange coupling and strain effects was obtained from the Mn $L_{2,3}$ soft x-ray absorption spectroscopy.