Fourier-transform infrared spectroscopy of colloidal α-, β- and γ-ferric oxide hydroxides

Abstract

Fourier-transform infrared spectra and surface properties of colloidal α-, β- and γ-ferric oxide hydroxides [Fe(O)OH], which were synthesized and aged in this laboratory, have been studied. The spectrum of the α phase has a strong absorption band at 3150 cm^–1 and two weak ones at 3485 and 3661 cm^–1. That of the β phase has a strong band at 3480 cm^–1, a weak band at 3659 cm^–1 and two very weak bands at 3686 and 3723 cm^–1. That of the γ phase has a strong band at 3160 cm^–1, a weak band at 3624 cm^–1 and a very weak band at 3528 cm^–1. The changes of these bands by the adsorption of heavy water, water and methyl iodide molecules and cupric ions have been studied in detail and the various bands were assigned to various OH groups with respect to the crystal structures of these materials.