A theoretical study of the magnetic and magneto-optical properties of the Pr-substituted YIG

The influence of Pr³⁺ substitution on the magnetic and magneto-optical properties of YIG is analyzed by using quantum theory. The temperature dependence of the Pr³⁺ magnetic moment is calculated in the 4.2-300 K temperature range. The Faraday rotation (FR) and Faraday ellipticity spectra at photon energies between 0.8 and 6 eV are determined as well. It is shown that the Pr³⁺ contributions to FR and to the magnetic moment depend strongly on the splitting of the 4f² configuration induced by the crystal field and the Fe-Pr superexchange interaction. The resonance frequencies are mainly determined by the splitting of the 4f5d configuration. Good agreement between calculated and measured values of both the magnetic and magneto-optical properties proves the correctness of the model and of the parameters used