Abstract
Bi x Sb2-x Te 3 (x=0.4 and 0.5) powders were pressed and sintered by passing a high-density electric current under nitrogen ambient. The electrically sintered Bi x Sb 2-x Te 3 was found to have a marked increase in Hall mobility but a moderate reduction in carrier density. We propose that electric-current induced atomic diffusion plays an important role in modulating crystal defects in Bi x Sb 2-x Te 3 compounds. The hot-pressed Bi0.4 Sb1.6 Te 3 shows a threefold increase in Z T after electrical sintering process. With the electrical sintering approach we can preserve fine-grain microstructure, and hence low thermal conductivity of Bi x Sb 2-x Te 3 with reasonable electrical resistivity and Seebeck coefficient. © 2009 American Institute of Physics.