POLAR KERR ROTATION IN CO-DOPED HEXAGONAL FERRITES

Spectral dependences of the polar Kerr rotation on a series of the cobalt- and titanium-substituted single crystals of barium hexaferrites were measured in the visible and near infrared region. Kerr rotations obtained on the polished and etched (0001) surfaces were superior to the spectra obtained on the natural growth planes. The largest Kerr rotations exceeding 4 degrees at wavelengths of about 1800 nm were found for molar concentrations of cobalt approximately equal to 0.4. Kerr rotation hysteresis loops displayed small coercive force (500 Oe) and small remanent values with a strong unidirectional character. © 1990 IEEE