Spin-wave resonance in amorphous NiMn and NiMnPt alloy films

Özet

Spin resonance studies have been done on a series of amorphous thin films of NiMn, NiMnPt alloys prepared by flash evaporation technique [1]. Data were taken over a wide range of temperatures (4.2-300K) in cases where the applied magnetic field is either parallel or perpendicular to the surface of the films. We have analyzed the data by using a computer programme based on the solutions of the Landau-Lifshitz (LL) equation. Prom fits of our data tc the theoretical curves, we have found the uni-directional anisotropy $H_A$ the exchange stiffness A, bulk and surface anisotropy constants K's and k's, as a function of temperature. We have also observed that the uni-directional anisotropy rotates [2] freely towards the applied field direction.