SOL-GEL PROCESSING OF TITANIUM-CONTAINING THIN COATINGS .1. PREPARATION AND STRUCTURE

Using tetrabutylorthotitanate as a precursor, titanate coatings with a nd without modifiers such as SnO2 and Fe2O3 have been successfully obt ained. The hydrolysis and polycondensation mechanism is discussed in r elation to the sol-gel transition. The gel-formation region was obtain ed as well as stable-layer formation and phase-separation regions in t he Ti(OBun)4-C2H5OH-H2O system. Coatings deposited on glass substrates exhibited a strong tendency to aggregate and with increasing temperat ure to crystallize in anatase or rutile phases (500 and 1000-degrees-C , respectively). Structural characteristics of the gel products were i nvestigated by SEM, X-ray and electron diffraction measurements, as we ll as by small-angle X-ray scattering. It was established that after t hermal treatment at 500-degrees-C for 10 min, spherical aggregates wer e formed in the coatings, having an average radius of approximately 5. 1 nm.