Effective equation of a weak ferromagnet's nonlinear dynamics, describing domain boundary superlimit movement

Abstract The generalization of the effective equation of a weak ferromagnet's nonlinear dynamics has been proposed. We give its exact particular solution, describing the stationary domain boundary movement, including the region v > c , where c is the minimum phase velocity of the spin waves. The domain boundary width remains finite when v → c in contrast to the anisotropic σ-model of the n -field.