Titania ceramic materials modified with 5% antimony and 5% tungsten were prepared by the sol-gel method. For the antimony-modified material, a treatment with H2O2 was also performed, in order to obtain antimonic acid. The electric conductivity of the xerogels was measured at 25 degrees C in the relative humidity (RH) range 33-81%. At 25 degrees C, the electrical conductivity of the "as prepared" 5% Sb ceramic varies from 2.02 x 10(-5) S cm(-1) at 33% RH to 1.12 x 10(-2) S cm(-1) at 81% R.H. For the material treated with H2O2, the conductivity varies from 1.56 x 10(-5) to 2.37 x 10(-2) S cm(-1) for 33% and 81% R.H., respectively. For the tungsten-modified material, the conductivity varies from 1.02 x 10(-5) to 2.66 x 10(-3) S cm(-1) for 33% and 81 % R.H., respectively. The activation energies observed for proton conduction were 23.5 kJ mol(-1) for TiO2/W 5%, 22.9 kJ mol(-1) for TiO2/Sb 5% and 20.6 kJ mol(-1) for the material treated with H2O2. The highest activation energy was observed for untreated TiO2:24.8 kJ mol(-1). The conductivity values for the Sb-modified ceramics are superior to those reported previously for antimonic acid films, and approach the values reported for proton-conducting polymers, such as Nafion (R), making them a potential candidate for application as electrolytes in fuel cell systems. (c) 2004 Elsevier B.V. All rights reserved.