Applications of ion implantation to magnetic bubble devices

Ion implantation has become an important part of magnetic bubble technology. The damage produced by implantation places the implanted layer in a state of in‐plane compression. This can change the easy axis of magnetization from perpendicular to parallel to the surface in a material having a negative magnetostriction coefficient. Several magnetic effects result from the creation of a thin layer of in‐plane magnetization at the top of the magnetic bubble supporting material. These include flux capping of the bubbles, control of the allowable magnetic bubble states, formation of bubble guiding rails at the boundaries of implanted areas, and creation of a moving magnetic pole pattern for bubble propagation in an external rotating in‐plane magnetic field. Other observed effects include increases in lattice parameter up to ∠2% and enhancement of the etching rate of the material by as much as a factor of 1000. Implantation is now widely used to suppress hard bubbles, and there is the possibility that ion implant...