2005 Volume 46 Issue 11 Pages 2525-2529
N-type Bi1.9Sb0.1Te2.6Se0.4 alloys were prepared by a rapid solidification technique and subsequent hot-pressing method. The microstructure and thermoelectric properties of the alloys were investigated as a function of the hot-pressing temperature and pressure. The X-ray diffraction measurements indicate that the grains are preferably aligned with the c-axis perpendicular to the direction of the hot-pressing force by the hot-pressing. Hot-pressing at higher temperature promotes the grain growth in the alloys. The Seebeck coefficient (α) and electrical resistivity (ρ) decrease with an increase in the hot-pressing temperature, whereas the thermal conductivity (κ) increases. The specimens prepared at higher temperature greater than 733 K show better thermoelectric performance: the largest dimensionless figure of merit (ZT) is 1.08 at room temperature.