Magnetization Curling in Tapered Edge Films

A 90° curling of the magnetization occurs at those film edges perpendicular to the easy axis in films of 700–1800 Å thickness when the film edges are suitably tapered. This configuration replaces the closure domain state generally found at the edges of films in this thickness range. Theoretical calculations yield expressions for the preferred edge taper angle and the resultant distance in which the magnetization curling takes place. The expressions for the edge taper angle and the curling distance are given in terms of the anisotropy, exchange, and magnetization constants and the film thickness. The curling distances that occur in actual films are measured and found to be in good agreement with the theoretical predictions. Experiments showing the differences in switching behavior of tapered and nontapered films are described and correlated with theory.