Bismuth Substituted' Yttrium Iron Garnet Single Crystal Films Prepared by Sol--gel Method

摘要

Magneto--optic Faraday rotation effect and the amount of bismuth substituted in yttrium iron garnet single crystal films prepared by gel--coating on modified gadolinium-- gallium garnet substrates are investigated, where the gel is synthesized by a sol--gel reaction of nitrates and ethylene glycol. The coated gel is annealed in air at temperatures up to 660℃ for 4 h, which is about 300℃ lower than that of liquid--phase epitaxy. The maximum amount of Bi substitution is x = 2. 7 and the crystallization temperature of garnet phase decreases with the increase of x down to 520℃ for x = 2.7. In this film, a huge Faraday rotation of --8.1 × 10~4 (°)/cm at λ = 0.633 μm is obtained.