Ferromagnetic resonance linewidth mechanisms in annealed CoFeSiB glass-covered microwires

Magnetic relaxation of CoFeSiB glass-covered microwire under applied stress and Joule heating annealing was investigated by ferromagnetic resonance (FMR) linewidth experiments. We were able to identify the main damping mechanisms and to quantify these damping terms, showing the effect of annealing and applied stress on the damping terms. The study has shown that there are three main damping mechanisms responsible for the FMR linewidth: the Gilbert damping parameter, a damping mechanism due to anisotropy dispersions and two-magnon scattering. The Gilbert damping parameter is constant and not influenced by annealing and stress. The FMR linewidth is very sensitive to anisotropy dispersions and this mechanism has a considerable contribution to magnetic relaxation. The two-magnon scattering is an assignment of the inhomogeneities present in the samples.