A molecular approach to RuO2-based thin films: sol-gel synthesis and characterisation

RuO2-based coatings were prepared by a sol-gel route. RuO2 nanocrystalline films were obtained by dip-coating from alcoholic solutions of Ru(OEt)3 and subsequent thermal treatments in air or N2 between 100 and 400 C. Mixed RuO2-SiO2 coatings were synthesised starting from solutions of RuCl3 and [NH2(CH2)2NH(CH2)3Si(OMe)3]. The Si compound was used either as precursor for the SiO2 matrix or as complexing agent for the Ru ions, to synthesise ruthenium oxide-based nanoaggregates directly in the SiO2 glass. The microstructure of the systems was studied by XRD, while their surface and in-depth chemical composition was analysed by XPS. Furthermore, the thermal evolution of RuO2-SiO2 coatings was investigated by optical absorption. 41 refs.