Authors: Y. ÖNER, M. ÖZDEMİR, B. AKTAŞ, E. A. HARRIS
Abstract: Spin resonance studies have been done on a series of amorphous thin films of NiMn, NiMnPt alloys prepared by flash evaporation technique . 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. From fits of our data to 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  freely towards the applied field direction.