No abstract

The calculations of the Faraday rotation (FR) induced by the rare-earth (RE) ions in the RE-substituted iron garnets with RE=Ce, Pr, and Tb, based on quantum theory are presented. The FR contributed by the RE ions is caused mainly by the intraionic electrical dipole transitions between the 4fn and 4fn−1 5d configurations. The crystal field (CF) and the superexchange interaction are two crucial factors in determining the FR contributed by the RE sublattice. For the Ce3+ ion in Ce:YIG, the energy differece between the lowest CF split 5d level and the lowest CF split 4f level is 1.415 eV, hence the FR contributed by the Ce3+ ion at 633 and 1150 nm wavelengths have different signs. The splitting of the excited and ground configurations induced by CF is smaller for the Pr3+ and Tb3+ ions in Pr:YIG and Tb:YIG. Therefore, the FR at 633 and 1150 nm wavelengths in these garnets have the same sign. The theoretical results are in good agreement with experiments.

No abstract

The calculation of the contribution of the intraionic electric-dipole transitions between the 3d8 and 3d7 4p configurations of Ni2+ ions doped in barium ferrites to the Faraday effect is presented. It is shown that such transition is an important origin of the Ni contribution to the Faraday effect in the Ni-substituted barium ferrite. The energy difference between the mean energies of the 3d8 and 3d7 4p configurations is large. So the 496-nm wavelength (photon energy 2.5 eV) is far from the resonance frequencies. However, since the molecular field upon the Ni2+ ions is very large, the Faraday rotation at 496 nm produced by such transition is still large. Other possible origins are discussed briefly.

The Faraday rotation caused by electronic transitions between the 4f and 5d states of Ce3+ ions in paramagnetic CeF3 crystals is calculated. The crystal field is an important perturbation on the energy levels. An external magnetic field, together with an additive magnetic field introduced phenomenologically in our paper, would spilt every 4f state into two sublevels. The dipole transitions between these sublevels, and 5d states induce the Faradap effect.The Verdet constant at 0.6328 μm in the temperature range of 60-300 K is obtained. It is shown that our calculation is in good agreement with experiment.