THE INFLUENCE OF THE ADMIXING OF DIFFERENT MULTIPLETS ON THE SPIN MAGNETIC-MOMENT AND FARADAY-EFFECT OF RARE-EARTH IONS IN GARNETS

The influence of the admixing of the excited multiplets of the ground configuration with the ground multiplet on the spin magnetic moment of the crystal-field- and exchange-interaction-split ground state, the Faraday rotation and the magneto-optic coefficient induced by the rare earth ions in rare-earth-substituted garnets Y3-xRxFe5O12 (R=Ce and Pr) has been calculated in this paper. It is found that, in the case of Ce3+ ions, the admixing of the 4f1 2F7/2 multiplet with the F-2(5/2) multiplet makes the spin magnetic moment of the crystal-field- and exchange-interaction-split ground state increase by 140% and the Faraday rotation increase by 180% at 633 nm wavelength, and 150% at 1150 nm at 294 K. In the case of Pr3+ ions, the admixing of the 4f2 H-3(5) multiplet with the H-3(4) multiplet makes the spin magnetic moment of the crystal-field- and exchange-interaction-split ground state increase by 34% and the Faraday rotation increase by 59% at 294 K. The admixing of different multiplets of the Ce3+ ions makes the ratio between the magneto-optic coefficients at 50 and 294 K increase by 7% at 633 nm wavelength and 15% at 1150 nm.