Abstract
To investigate properties of Bi-substituted garnet film with many oxygen deficiencies, Bi, Ga : DyIG films have been prepared by sputtering in Ar+H2 gas (H2: 0∼5% in partial pressure) and post-deposition annealing for crystallization. When H2 concentration in sputter gas increased, the Bi content of the film decreased. The film sputtered in Ar+H2 crystallized as a garnet single phase at relatively low temperature (560°C for Bi=1.5) even when it had low Bi content and non-stoichiometry. The optical homogeneity of the film remarkably improved with increasing H2 concentration; optical scattering due to crystal grain boundaries was reduced further than that of the film sputtered in pure Ar. This is associated with many defects remaining in the crystal grains even after annealing, as confirmed by the extent of the linewidth of X-ray diffraction. The magnetization and Faraday rotation hysteresis of the films sputtered in Ar+H2 showed anomalous curves, which may have been caused by an impurity phase undetectable by X-ray diffraction measurement.
