Anisotropy Field Change by Annealing in He+/Ne+ Ion-Implanted Bubble Garnet Films

Bubble garnet films, (YSmLuGd)3 (FeGa)5O12, were implanted with He, N, and Ne ions at 100-200 keV and annealed at 350 to 600°C, and changes in the maximum lattice strain, (¿a/a)max, and in the effective anisotropy field, ¿(Hk-47¿Ms), were measured by double-crystal X-ray diffraction and ferromagnetic resonance. Lattice strain in layers implanted with He, N, and Ne ions decreased monotonically with annealing. The change in anisotropy field initially increases with heat treatment for samples implanted with heavy ion doses, then decreases. This increase was attributed to changes in the saturation magnetization Ms and magnetostriction coefficient ¿111.