Infrared absorption spectra of metal oxides

Abstract

In order to apply an infrared spectrometry to the analysis of nonmetallic inclusion in steel, the identification of corrosion products and the study of surface treatment on steel plate, infrared absorption spectra of 25 kinds of metal oxides (α-Al2O3, CaO, CeO2, Co3O4, CrO3, Cr2O3, CuO, FeO, α-Fe2O3, Fe3O4, MgO, MnO, NiO, PbO, PbO2, Sc2O3, α-SiO2, SnO, SnO2, TiO2, V2O3, V2O5, Y2O3, ZnO and ZrO2) were examined in detail. The spectra were measured by means of potassium bromide disk technique and nujol paste technique over the frequency region between 1400 and 400 cm-1. Several of the oxides were also studied for their far infrared spectra between 400 and 60 cm-1. These oxides were found to have specific absorptions in the measured region, and showed definite correlations between their spectra and crystal structures. (1) Oxides of iron, FeO, α-Fe2O3, γ-Fe2O3 and Fe3O4, can be easily identified by comparison of their spectra. (2) CrO3, PbO, SnO and V2O3 give specific absorptions quite distinguishable from those, repectively, of Cr2O3, PbO2, SnO2 and V2O5 (3) NaCl type oxides, MgO, CaO, FeO etc., have only one absorption at near 400 cm-1, so that a force constant of M-O bond can be easily calculated as a diatomic molecule: e. g., that of ferric oxide, FeO, was 1.24md/A. (4) Spinnel (MgAl2O4) type oxides have coupling absorption at near 570 and 390 cm-1. (5) Sillicon dioxide can be easily distinguished from the mixed sample of FeO, MnO, SiO2, Cr2O3 and Al2O3, in the analysis of nonmetallic inclusion in steel. It was recognized, moreover, that the absorbance, log(I0/I), and quantity of SiO2 were linearly correlated. © 1967, The Japan Society for Analytical Chemistry. All rights reserved.