Magnetooptical properties of cerium-substituted yttrium iron garnet single crystals for magnetic-field sensor

The magnetooptical properties and magnetic-field-sensing properties of bulk Ce-substituted YIG (Ce x Y 3− x Fe 5 O 12 ) crystals were studied. There was an absorption edge at 1200 nm and a large negative Faraday rotation was obtained. Faraday rotation was increased to a greater extent by Ce substitution than by Bi substitution. The magnetic-field sensitivity of Ce 0.24 Y 2.76 Fe 5 O 12 was 0.0048% m/A which was larger than that of (BiGdLaY) 3 (FeGa) 5 O 12 . The optical current transformer (CT), using a Ce:YIG crystal as a sensor head, could measure the alternating steady state, faulting, breaking and reclosing currents. These results suggest that cerium-substituted yttrium iron garnet is a high-performance material suitable for magnetic-field (or electric-current) sensors.