Magnetic and crystalline properties of ion-implanted garnet films with plasma exposure

The implantation induced anisotropy field change, ΔHk, and lattice strain, Δd/d, in ion implanted films have been found to be enhanced considerably by exposing films to plasma of H2, He, Ne and Ar gases in the substrate temperature greater than 100°C. The enhanced ΔHk is twice as large as the as-implanted value in typical experiments, and it is comparable to the ΔHk of the hydrogen ion implanted layer. The enhanced ΔHk of the exposed film decreases greatly with increasing annealing temperature, but this can be prevented coating the surface with an SiO2layer. The changes of ΔHk profiles in plasma exposure are obtained by FMR technique. ΔHk is enhanced not only at the surface but also deep in the implanted layer. The origin of this effect is probably ascribed to the diffusion of the residual hydrogen into the implanted layer.