Exchange coupling between a soft and a hard ferromagnetic thin film

Abstract
An investigation of exchange coupling mechanism in a double film formed of the amorphous Co1−xTix and polycrystalline Co1−x−yPtxTiy layer is reported. The thin films were prepared by rf diode sputtering. The amorphous layer presents the characteristics of a soft ferromagnet (Hc<1Oe) and an in-plane induced uniaxial anisotropy Hk. The CoPtTi hard layer exhibits a large Hc. The exchange mechanism was characterized by the shift Hs of the in-plane hysteresis loop, and by ferromagnetic resonance measurements. The effect of interface contamination by oxygen upon the interfacial exchange constant is pointed out.