Characteristics of p-type Bi0.5Sb1.5Te3 compounds doped with Te

p-type Bi0.5Sb1.5Te3 compounds doped with 4.0 wt% Te were fabricated by hot pressing in the temperature range 380 to 420 degrees C under 200 MPa in Ar. X-ray diffraction and transmission electron microscopy were used to examine the microstructure. The microstructure was relatively dense and the grains were oriented through the hot pressing. With increasing pressing temperature, both the density and the degree of preferred orientation of grains increased, resulting in an improvement in the figure of merit. The values of the figure of merit obtained along the directions perpendicular to and parallel to the pressing direction for the compounds hot pressed at 420 degrees C were 2.69 X 10(-3) K-1 and 1.92 x 10(-3) K-1 respectively. (C) 1998 Elsevier Science B.V.