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 ΔH
_p
in the ferromagnetic resonance field of surface spin wave modes in an ion-implanted layer of YIG film during optical illumination. The H
₂
⁺
or He
⁺
implanted films were annealed in a hydrogen gas atmosphere. The results on annealing show various ΔH
_p
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.