Magnetooptical and Reflectivity Studies of SrTiO₃

Abstract

Faraday rotation spectra were measured in single crystals of SrTiO₃ between 1.7 and 3.2 eV at room temperature and at 20 K. The rotation showed a monotonous increase as the absorption edge was approached. In a single crystal with thickness of 0.5 mm, it took a value as large as 7.7° at 400 nm for magnetic field of 1 T. The center of dispersion of the magneto-optical spectrum was determined to be 4.19 eV. This value agreed with the peak energy position (=4.2 eV) of the imaginary part of dielectric function, ε₂ deduced from the reflectivity spectrum meas red between 0.5 and 20 eV.