Amorphous materials of the [(ZrO2)(0.92)(Y2O3)(0.08)](1-x)(RuO2)(x) system, where 0 less than or equal to x less than or equal to 0.3 (mol), have been obtained by sol-gel processing from Ru (III) acetyl-acetonate, zirconium (IV) n-propoxide and hydrated yttrium-acetate. Scarlet, translucent and uniform gels were achieved. To study the evolution of sols and the materials obtained, infrared spectroscopy was applied. Their crystalline evolution and microstructural changes have been investigated as a function of thermal treatment in the temperature range 300-1400 degrees C by DTA-TG, X-ray diffraction and SEM-EDX. At low temperatures (similar to 500 degrees C), yttria-doped cubic zirconia is obtained and RuO2 is incorporated into the structure in solid-solution up to 10 mol% at this temperature. (C) 1997 Elsevier Science B.V.