Effect of boron-doping on thermoelectric properties of rutile-type titanium dioxide sintered materials

The electrical and thermal transport properties of boron-doped rutile-type TiO(2) were investigated. The rutile-type TiO(2) powder was mixed with B(2)O(3). TiB(2) or B and the mixtures were sintered using the pulse current sintering method at 1473K. Secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) measurements showed that B or TiB(2) addition was effective for boron-doping. The boron was well distributed in the sintered materials and the unit cell volume of rutile increased as the amounts of added B or TiB(2) increased. The electrical resistivity and Seebeck coefficient at 300 K decreased with an increase in the unit cell volume indicating that boron addition leads to an increase in the electron concentration. Thermal conductivity at room temperature also decreased with an increase in unit cell volume and as a result the thermoelectric figure of merit for rutile-type TiO(2) was enhanced by boron-doping. (c) 2010 Elsevier B.V. All rights reserved.