Raman spectra of FeO, Fe3O4, α-Fe2O3, α-FeOOH, and γ-FeOOH, the common products of iron oxidation, have been measured. The spectra of FeO and Fe3O4 appear to be identical. Armco iron oxidized in air at 250°C was examined by Raman spectroscopy after varying periods of exposure and the surface film was found to contain Fe3O4 and α-Fe2O3.

The use of Raman and infrared spectroscopy to analyze surface films on metals is described. Surface films formed on lead by reaction with aqueous buffer solutions were examined. The composition of each film was determined by Raman spectroscopy while the sample was in the solution. Multiple reflection infrared spectra of dry samples confirmed the Raman results. The Pourbaix diagram for lead in water was calculated, and potentiostatic exposures were conducted to see if the compounds corresponded to those predicted in the diagram. Tetragonal normalPbO was found to occur over a much greater range of potentials than thermodynamic stability would indicate.

The feasibility of resonance Raman spectroscopy in the detection of hazardous chemicals in water has been tested on some nitrophenol-based pesticides and fungicides. In most cases, detection limits below the parts per million level were obtained. The method was also tested on an artifically polluted river water sample.

The normalPb‐H2O‐SO4 Pourbaix diagram was investigated by examining potentiostatically oxidized lead samples using Raman and infrared spectroscopy. In 0.1M sulfate solutions surface film compositions were not in complete agreement with predictions of the calculated potential‐pH diagram. The Pourbaix diagram did not predict the formation of normalPbO under any conditions; however, spectra indicated the presence of the oxide at certain potentials in acid and neutral solutions and at all potentials above the immunity region in basic solutions. Spectroscopic identification of insoluble surface species was in agreement with potentiodynamic polarization curves.

The normalPb‐H2O‐normalCl Pourbaix diagram was investigated by examining potentiostatically oxidized lead samples using Raman and infrared spectroscopy. The surface films formed in 0.1MnormalHCl solution were those predicted by the potential‐pH diagram. In neutral and basic solutions, the film compositions were not as predicted by thermodynamic calculations, although potentiostatic results agreed very well with potentiodynamic polarization curves. Two polymorphs of normalPbO were found at different potentials in pH7 solutions, the orthorhombic form at low potentials and the tetragonal form above +0.18V vs. NHE. Infrared spectra gave indications that orthorhombic normalPbO is formed by deposition from solution while tetragonal normalPbO forms from the reaction of water with the metallic lead surface.