Planar domains in ion-implanted magnetic bubble garnets revealed by Ferrofluid

Abstract

Magnetic closure domains in ion-implanted surface layers associated with magnetic bubbles in the underlying garnet films have been revealed by the Bitter pattern method using Ferrofluid. This is the first direct observation of the planar magnetization produced by ion implantation in garnets with negative magnetostriction. The closure domains are very sensitive to an in-plane magnetic field and become too small to observe in rotating fields as large as those used in field-access bubble devices. Closure domains around an ion-implanted pattern in a garnet film and in a thin film of Permalloy evaporated onto a bubble garnet are also shown.