Effect of a thin Permalloy layer on bubble-domain stability

Abstract

This letter reports a theoretical and experimental investigation on the effect of placing a thin Permalloy layer atop bubble‐domain materials. The Permalloy layer shifts and broadens the domain static bias field range because of the increase of bubble energy. The bias field shift effect starts diminishing in the presence of an in‐plane field. The experimental observations are satisfactorily explained by an analytical model in which the magnetostatic coupling energy between Permalloy and bubble is first calculated and then extended to Thiele's stability theory by a pertubation method.