SnO2–TiO2 solid solutions for gas sensors

Abstract Mixed oxide gas sensors of SnO 2 –TiO 2 have been prepared in the form of polycrystalline ceramics and rf-sputtered thin films. The influence of the chemical and phase composition on the crystallographic structure, microstructure and sensor performance is discussed. The measurements of the electrical resistance as a function of hydrogen partial pressure have been performed with air or argon as a reference gas. The results are analyzed in terms of the surface and bulk interaction models. It is proposed that hydrogen detection in air involves the preadsorbed O − species. Hydrogen interaction with the SnO 2 –TiO 2 system in Ar atmosphere is governed by bulk diffusion of oxygen vacancies.