High-throughput characterization of Bi xY 3− xFe 5O 12 combinatorial thin films by magneto-optical imaging technique

Abstract

Bi x Y 3− x Fe 5O 12 thin films have been grown on GGG (Gd 3Ga 5O 12) (1 1 1) substrates by the combinatorial composition-spread techniques under substrate temperature ( T sub) ranging from 410 to 700 °C and O 2 pressure of 200 mTorr. In order to study the effect of substrates on the deposition of Bi x Y 3− x Fe 5O 12 thin films, garnet substrates annealed at 1300 °C for 3 h were also used. Magneto-optical properties were characterized by our home-designed magneto-optical imaging system. From the maps of Faraday rotation angle θ F, it was evident that the Faraday effect appears only when T sub = 430–630 °C. θ F reaches to the maximum value (∼6°/μm, λ = 632 nm) at 500 °C, and is proportional to the Bi contents. XRD and EPMA analyses showed that Bi ions are easier to substitute for Y sites and better crystallinity is obtained for annealed substrates than for commercial ones.