Determination of the magnetic damping constant in NiFe films

A two-dimensional, dynamic, micromagnetic model of a thin strip of permalloy is described and used to model the magnetization dynamics of the strip as it is subjected to a transverse step field. The numerical results are compared to experimental data. The experimental precession frequency is matched by varying H-k, the longitudinal, uniaxial, magnetocrystalline anisotropy field. The damping is matched by varying alpha, the phenomenological damping parameter in the LLG equation. A good fit to the data was obtained with a single damping constant of alpha=0.013. (C) 1999 American Institute of Physics. [S0021-8979(99)65008-3].