Annealing time dependence of optical and magneto-optical properties of bi-substituted garnet films

The reflection mode techniques of variable angle of incidence spectroscopic ellipsometry and normal incidence Kerr spectroscopy have been used in tandem to characterize thin (3200 Angstrom) films of (Bi_2.0Dy_1.0)(Fe_3.5Ga_1.0)O_x which were sputter deposited on glass substrates and crystallized by post-annealing. Nonlinear regression was used to find the optical constants of the garnet film and the thickness of the film, after which the magneto-optical constants of the film were calculated analytically from the Kerr rotation and ellipticity data. Results are presented for several films as a function of post-annealing time, and suggest that variation in Bismuth content in the films with annealing time is responsible for the variation in the optical and magneto-optical properties of the films. The purpose of this work is to study the effects of post-deposition annealing conditions on the optical and magneto-optical character of the film.