Domain-wall energy measurements in Ni-Fe-Co films

Abstract

The domain-wall energy density σw in 65/15/20 Ni-Fe-Co films has been determined using the domain-tip propagation technique. The method involves the measurement of the threshold field for tip motion of a reverse domain in a low-coercive-force channel as a function of channel width. The two models of tip motion which have been proposed, viz, translation and tip elongation, give rise to different expressions for the propagation threshold and, consequently, different calculated values of σw. Experimental data show that the elongation model is preferable, and σw has been calculated using this model. The wall energy is presented as a function of film thickness in the range 600–2200 Å and is compared with theoretical values. The experimental results are found to be generally higher than the theoretical wall energy.