Magnetooptical polar kerr effect in ferrimagnetic garnets and spinels

The complex polar Kerr spectra of ferrimagnetic garnets and spinels have been studied in the spectral region from 2 to 6 eV. The influence of Ga, Al, In, Sc, Pr, Sm, Tb and Ho on garnet spectra is presented and discussed. The reflectivity and dielectric tensor element spectra were also obtained for selected samples and the data is then used in the explanation of the spectra in terms of charge transfer transitions. In particular the bands near 3.4, 3.6, 4.3 and 4.7 eV are respectively assigned to the transitions to t2g, e, t2and egorbitals. The effect of polishing on reflectivity spectra of lithium ferrite is briefly discussed.