A coupling phenomenon between the magnetization of two ferromagnetic thin films separated by a thin metallic film--Application to magnetic memories

A new type of magnetic interaction between two ferromagnetic thin films separated by a third metallic nonmagnetic thin film is studied. This coupling tends to bring the magnetization of the ferromagnetic materials into parallel alignment. The coupling is shown to be dependent upon the intermediate material and its thickness, and on the nature of the ferromagnetic media present. These interactions are observed for intermediate metal thicknesses up to 300 Å in the case of Palladium. The measured surface energy of this coupling is of the order of 0.1 erg/cm². A study of the variation of the coupling with temperature is given.