Semiconducting properties of nonstoichiometric TiO2-x ceramics

Ceramics containing titanium oxides were prepared using extrusion technology and thermal treatment in two stages: sintering at normal atmospheric conditions at 1000 and 1200 °C and annealing in high vacuum conditions at 950 and 1150 °C. Electrical properties such as thermopower and electrical conductivity of cylindrical specimens have been studied at temperature range from the room temperature up to 350 °C. Activation energy of the process has been determined from conductivity curves. Obtained thermopower values are in the range from 68 up to 105 mV at temperature gradient between the hot and cold ends of the samples at 300 °C, while activation energy values are from 0.03 to 1.16 eV