Surface effects on electrical and magnetic properties of Ni75.2Mn23.6Pt1.2 alloy films

Finally, FMR measurements were used to probe the magnetic state. We considered the simplest form of the Hamiltonian and used a model based on the Landau-Lifshitz equation. By a rigorous analysis of the angle dependence of the FMR measured at several temperatures, we determined the values of the bulk and surface anisotropy constants, and the exchange stiffness constant. The fitting parameters show that the magnetic ordering is modified significantly by film thicknesses due to the surface anisotropy fields.