CHARACTERIZATION OF RUO2-BASED FILM ELECTRODES BY SECONDARY-ION MASS-SPECTROMETRY

Concentration depth profiles of Ti-supported RuO2-TiO2 films, prepared by pyrolysis of ruthenium(III) chloride hydrate and titanium diisopropoxide bis-pentane-2,4-dionate, have been studied by secondary ion mass spectrometry (SIMS). The Ru-102:Ti-48 ion intensity ratio vs. the nominal concentration of ruthenium oxide was followed for samples obtained from precursors dissolved in different solvents. The dependence on bombarding time of ion intensity profiles for other species, such as O- (m/z = 16), OH- (m/z = 17), (TiO+)-Ti-46 (m/z = 62), (TiOH+)-Ti-50 (m/z = 63) was also studied. The mixed oxide films were characterized by cyclic voltammetry. The results of the combined research support the idea that microstructural and chemical impurities are concentrated in the outermost part of the film. This phenomenon seems to depend on the composition of the solvent used for the precursor salts.