Measurement of the damping parameter from the low field microwave excitations of domain walls

The effect of damping is added to theory of low field microwave excitations at the domain walls, using a Gilbert damping term in the equations of motion. The equations for mθand mφdo not retain their eigenvalue equation form. Hence a Green's function technique is used, to calculate the r.f. moment that develops across the wall. The damping parameter is varied and the ratio of the domain wall moment to the r.f. moment of the uniform mode is matched with the experimental ratio. The damping parameter thus obtained is found to be larger than that obtained from the uniform mode line width as is observed for the values reported from wall velocity measurements.