Origin of effective anisotropy field change induced by ion implantation in magnetic garnet films

The origin of effective anisotropy field change induced by ion implantation in magnetic garnet films has been investigated using films with uniform strains. Uniform strains were produced by ion implantation into very thin (600 A) garnet films. Using such ion-implanted samples, strain, saturation induction 4πMs, magnetostriction coefficient λ
111
and effective anisotropy field change Δ(Hk-4πMs) were measured. It was found that Δ(Hk-4πMs) is mainly brought about by the magnetostriction effect for both H
2
+ and Ne+ implantations. Different dependences of Δ(Hk-4πMs) on strain between H
2
+ and Ne+ implantations are attributed to different dependences of λ
111
and 4πMs. A large value of Δ(Hk-4πMs) for H
2
+ implantation originates from a large magnitude of λ
111
.