Fabrication and thermoelectric properties of n-type SbI3-doped Bi2Te2.85Se0.15 compounds by hot extrusion

The n-type 0.1 wt% SbI3-doped Bi2Te2.85Se0.15 compounds were fabricated by hot extrusion in the temperature range 300-510 degrees C under an extrusion ratio of 20:1. The extruded compounds were highly dense. The grains were small, equiaxed (similar to 1.0 mu m), and contained many dislocations due to the dynamic recrystallization during the extrusion. The grains were also preferentially oriented through the extrusion. The bending strength and the figure of merit of the compounds, hot-extruded at 440 degrees C, were 97 MPa and 2.62 x 10(-3)/K, respectively. (C) 1998 Elsevier Science Ltd.