On computation of relaxation constant α in Landau-Lifshitz-Gilbert equation

Due to the quasi-classical kinetic equation (QKE) for the magnon distribution function to calculate the velocity of the domain wall motion V in magnetic fields H>Ha, where Ha− magnetic anisotropy field. Based on the comparison of this formula for Vthe analytic expression of relaxation constant α in Landau-Lifshitz-Gilbert equation was found. We used the detected correlation between the system׳s entropy and the environment׳s resistance force, and obtained an expression for the spin-lattice braking force that is applied to the moving domain wall. We calculated the mobility ratio of the domain wall.