Transport properties of (Sn,Ti)O-2 polycrystalline ceramics and thin films

Polycrystalline ceramics and thin films of (Sn,Ti)O-2 were prepared with th e aim of investigating the mass and electronic charge transport as well as the electronic structure. The re-equilibration kinetics were monitored by m easuring the de electrical conductivity as a function of temperature, 850 K < T < 1050 K, and oxygen partial pressure, 10(-15) Pa < p(O-2) < 10(5) Pa. The chemical diffusion coefficient was found to be independent of p(O-2). The energy of the forbidden band gap, evaluated on the basis of optical mea surements, is presented as a function of tin dioxide mole fraction. The inf luence of the chemical and phase composition on the microstructure, electro nic and optical properties of polycrystalline ceramics and thin films of (S n,Ti)O-2 is discussed. (C) 1999 Elsevier Science B.V. All rights reserved.