Enhanced exchange anisotropy between antiferromagnetic PtMn and ferromagnetic Co system by AuCu underlayer

The introduction of a Au50Cu50 (in at. %) seed and dynamic-stress-induced Pt50Mn50 ordered-assisting layer into PtMn/Co exchange-coupled films resulted in a unidirectional anisotropy constant Ke≒0.37 erg/cm2, approximately 20% larger than the previous reported results and in a strong PtMn(111) crystalline orientation even after thermal annealing. It was considered that the former was due to the increase in exchange-coupling density with the strong PtMn(111) orientation and to the increase in lattice distortion of the PtMn film with excessive dynamic-stress-induced PtMn ordered-assisting effect of the AuCu film. The cause of the latter was that the AuCu film effectively functioned as a seed layer of the PtMn film.