Sputter Deposition of Ce-Substituted Iron Garnet Films with Giant Magneto-Optical Effect

Epitaxial monocrystalline and polycrystalline films of highly Ce-substituted YIG have been prepared by rf-diode sputtering. The threshold temperature for epitaxial growth increased with Ce content at a rate of 80°C/CE ion from 390°C of YIG film. Epitaxy was achieved for Ce content up to 1.5 per formula unit. The Ce-substitution induced exceptionally large Faraday rotation in the visible and near infrared regions, the factor per Ce ion being 2 × 10⁴ deg/cm at ¿ = 633nm and ¿1.3 × 10⁴ deg/cm at 1150 nm. The polycrystalline films were obtained in single garnet phase for Ce content up to 0.7. They were fully crystallized when post-annealed above 775°C. The films were quite homogeneous and grain boundaries were indiscernible. Thus, Ce:YIG films are a very promising magneto-optical material.