Spin-Wave Resonance in Epitaxial Fe–Ni Films and in Coupled Double Layers of Epitaxial Fe–Ni (Ferromagnetic)—Fe–Ni–Mn (Antiferromagnetic)

Abstract

We have studied spin-wave resonance at 9.3 GHz in epitaxial [111] permalloy films both alone and in contact with an antiferromagnetic Fe–Ni–Mn film. In the first case we find very weak higher-order spin-wave modes such that the intensity ratio I (higher order)/I (principal) <10−3. From this we conclude that the surface anisotropy constant is Ks<0.1 erg/cm2. In the second case, we observe ferro-antiferro-magnetic coupling across the interface. This is exhibited by the excitation of strong higher-order modes of odd symmetry, which disappear upon heating the Fe–Ni–Mn to its paramagnetic state. This is correlated with a shift of the hysteresis loop of the Permalloy, caused by the same interaction, which also disappears upon heating.