Bi3Fe5O12: Dy2O3 composite thin film materials for magneto-photonics and magneto-plasmonics
Optical Society of America
Electron Science Research Institute
Large Faraday rotations, when achieved simultaneously with low optical losses, lead to obtaining high magneto-optic (MO) figures of merit in bismuth-substituted garnet-type material systems. Demonstrating high MO figures of merit typically requires the synthesis of garnet materials with high bismuth substitution levels (close to 3 Bi atoms per stoichiometric formula unit). In our previous experiments, garnet layers sputtered from a target of nominal stoichiometry Bi3Fe5O12 in pure argon atmosphere showed negligible amounts of specific Faraday rotation after annealing, in contrast with results reported typically for pulsed laser deposition of this material in plasma chemistries containing oxygen. We co-sputter Bi3Fe5O12 together with Dy2O3 in pure argon plasma, and obtain the garnet-type composite thin films on glass substrates possessing a specific Faraday rotation in garnet-Dy2O3 composite films in excess of 14°/μm at 532 nm and a coercive force as low as 100 Oe.