Studies on antiferromagnetic/ferromagnetic interfaces

Abstract The spin valve with a synthetic pinned layer serves as an excellent system to study the interfacial properties of antiferromagnetic—ferromagnetic films (AFM/FM). Using this system, we have unambiguously determined that the direction of the exchange bias is totally determined by the direction of magnetization of the ferromagnetic films and not by the applied magnetic field. The two surfaces of 50 A antiferromagnetic thin film are able to provide exchange bias at the interfaces of both the upper and lower ferromagnetic films. Furthermore, the exchange bias can be set along any direction for the polycrystalline AFM/FM films. The exchange coupling of AFM/FM films appears to occur at the AFM/FM interface where the surface spins in the matching grains favor exchange interactions.