Absorption Spectrum of an Antiferromagnetic Rare-Earth Garnet Dy₃Al₅O₁₂ above and below the Néel Temperature

Abstract

The absorption spectrum of a Dy³⁺ ion in dysprosium aluminum garnet in the paramagnetic state has been investigated in the region of 15,000 to 5,000 cm⁻¹. By observing the Zeeman effect in both pulsed and stationary magnetic fields, the g_z-values of the lowest three levels of the ⁶H_15⁄2 ground state split by crystalline-field and of the three levels of the ⁶F_5⁄2 excited state split by crystalline-field have been determined. From the splittings of the absorption lines corresponding to the ⁶H_15⁄2→⁶F_5⁄2 transition in the antiferromagnetic state, the internal fields acting on the Dy³⁺ ions in the ground and the ⁶F_5⁄2 excited states have been estimated to be 6.2 and 6.8 kOe, respectively.