Contribution of three-magnon scattering to Gilbert damping at elevated temperatures

Gilbert damping is a key parameter representing the energy loss in the Landau–Lifshitz–Gilbert equation, which describes the dynamics of magnetization and is crucial in micromagnetic simulations. We have developed an analytical method to calculate Gilbert damping based on the contributions from the three-particle magnon scattering process. By incorporating the exchange, anisotropic, and demagnetization energies, we applied this method to determine Gilbert damping at different temperatures. Our calculation shows that, near the Curie temperature, the calculated damping equals around 80% of the results obtained from the coarse-graining method proposed by Feng and Visscher in 2001, which means that three-magnon scattering gives a dominant contribution to Gilbert damping. This research may give useful insights into the relationship between Gilbert damping and magnons.