Dynamic properties of laser-annealed, Ga-substituted EuYIG bubble films

Abstract

Laser annealing induced changes in Ga-substituted EuYIG epitaxial bubble films were studied using FMR, bubble statics, SQUID magnetometry, and dynamic bubble translation experiments employing high speed photography. Comparing annealed to as-grown films, domain wall mobility and saturation velocity were observed to increase up to 50% while static coercivity Hcs was reduced by as much as one-third. Both an increase in exchange A and a decrease in damping α appear to contribute to enhanced mobility; we attribute the variations of both A and α to the interchange of Ga and Fe between crystal lattice sites brought about by laser annealing. The mechanism by which H cs was reduced is less clear, but may follow from the reduction of stress during annealing.