Wavelength‐modulated spectra of some Fe3+ oxides

摘要

The wavelength‐modulated reflectivity spectra in the visible and near uv of GdIG, LuFeO3, FeBO3, Fe2O3, Fe[NiFe]O4, and BaFe12O19 are reported. Features of both the exciton sideband and the charge‐transfer spectra are observed. Comparison of these spectra allows some site assignments to be made. In particular the octahedrally coordinated Fe3+ ion is found to contribute a characteristic charge‐transfer spectrum that occurs at lower energies than the tetrahedral Fe3+ charge‐transfer spectrum. A further charge‐transfer process between octahedral and tetrahedral Fe3+ sites is suggested to explain the garnet spectra.