Magneto-Optics of Dy3+ Ion in Low-Symmetric Orthoaluminate Structure

Abstract

Magnetic susceptibility and the Faraday effect in orthorhombic DyAlO₃ single crystals were studied along the crystallographic b-axis, the axis of easy magnetization, in a temperature range 78–300 K. The Faraday rotation was measured on the basis of the temperature and spectral dependencies of the rotation angles θ of the major axis of the ellipse of light radiation polarization in a wavelength range 440–750 nm. At a wavelength of 506 nm, the dependence of the Verdet constant V on the magnetic susceptibility χ_M was observed to be linear in a temperature range 85–300 K, and the paramagnetic Verdet constant C_p was calculated. A comparative analysis of the constants C_p and the effective frequencies ω₀ of allowed transitions in cubic R₃Al₅O₁₂ garnets and RAlO₃ (R = Tb³⁺, Dy³⁺) orthoaluminate crystals was carried out in terms of the local site symmetry for rare-earth ions. The possibility of practical magneto-optical applications of the DyAlO₃ crystals is briefly discussed.