Electrical conductivity, thermoelectric power and equilibration kinetics of Nb-doped TiO2

This work considers the equilibration kinetics of Nb-doped TiO2 single crystal (0.066 at% Nb) during oxidation and reduction within wide ranges of temperature (1073 K – 1298 K) and oxygen activity (10-14 Pa - 105 Pa). The associated semiconducting properties were determined using electrical conductivity and thermoelectric power measurements. It is shown that the chemical diffusion coefficient in the strongly reducing regime, p(O2)<10-5 Pa, is four orders of magnitude larger than that in reducing and oxidizing regimes, 10 Pa <p(O2)