Phase Relaxation of Electrons in Disordered Thin Ferromagnetic Films

The phase relaxation caused by scattering off spin wave excitations in disordered ferromagnetic films is considered. In the case that the spin wave spectrum is gapped, it is shown that the corresponding phase relaxation rate at temperatures above the gap follows a linear dependence in both two and three dimensions, similar to what has been found previously for clean systems. In the absence of the gap the behavior is controlled by the spin wave damping characteristics, typically leading to fractional power laws in temperature. The effect of finite external magnetic field is considered and shown to affect the prefactor of the linear T law.