INVESTIGATION ON THE FORMATION OF RUO2-BASED MIXED-OXIDE COATINGS BY SPECTROSCOPIC METHODS

Surface species formed as a function of the temperature during the pre paration of RuO2/TiO2 mixed oxide films were identified by emission FT -IR and FT-Raman spectroscopy. The formation of surface carbonyls from precursor mixtures of hydrated RuCl3 and titanium diisopropoxide bis- 2,4-pentanedionate was confirmed. The intensity of the CO stretching b and increases with decreasing ruthenium content due to the increasing dispersity of the noble metal. The negative emission bands of the coat ing 20%Ru + 80%Ti proves the occurrence of a segregation phenomenon re sulting in a TiO2-enriched surface layer. The results obtained are in agreement with those of former me asurements by simultaneous thermogra vimetry-differential thermal analysis (TGA-DTA), thermogravimetry comb ined with mass spectrometry (TGA-MS) and secondary ion mass spectromet ry (SIMS).