Velocity of domain walls in an epitaxial yttrium-europium garnet film

Abstract

Measurements of magnetic domain velocity by domain transport methods in an epitaxial Y2.4Eu0.6Ga1.2Fe3.8O12film have yielded values as high as 2800 cm/sec with no sign of saturation. These measurements conflict with those reported recently by Callen et al., who deduced a saturation velocity of 1300 cm/sec from bubble collapse measurements made on films of the same composition. It is suggested that the discrepancy is due to the wall velocity reaching momentarily the Walker breakdown velocity in the bubble collapse technique, which then leads to a relatively immobile spin configuration similar to the one reported recently for hard magnetic bubbles.