Photoinduced Effect on Magnetic Properties of Ion-Implanted YIG Thin Films--Resonance Field Dependence on Annealing Temperature in Hydrogen Atmosphere

The photoinduced effect studied here is the decrease ¿Hp in the ferromagnetic resonance field of surface spin wave modes in an ion-implanted layer of YIG film during optical illumination. The H2⁺ or He⁺ implanted films were annealed in a hydrogen gas atmosphere. The results on annealing show various ¿Hp behavior caused by the implanted and diffused hydrogen, and the formation of a large anisotropy in the surface layer of the He⁺-implanted films. Proposed models for changes in the chemical reaction between hydrogen and ferrous ions, and the origin of the large anisotropy, are discussed.