Thermoelectric properties of Tl9BiTe6

Polycrystalline-sintered samples of TI9BiTe6 have been prepared by hot pressing, and the thermoelectric properties have been measured in the temperature range from room temperature to about 700 K. The electrical resistivity is about 10 times higher than those of state-of-the-art thermoelectric materials, and shows a positive temperature dependence. The Seebeck coefficient is positive in the whole temperature range, showing p-type semiconductor characteristics. The maximum value of the power factor of the sample is about 6.2X10(-4) W m(-1) K-2 at 590 K. The thermal conductivity is extremely low comparable to those of state-of-the-art thermoelectric materials. The maximum value of the thermoelectric figure of merit ZT is 0.86 at about 590 K. (C) 2002 Elsevier Science B.V. All rights reserved.