Thermoelectric Properties of Bi-Sb Sintered Alloys Prepared under Unidirectional High Pressure

Abstract

Ultra fine powder of Bi₉₁Sb₉ was sintered under unidirectional high pressure. The powder was prepared by the hydrogen plasma-metal reaction method. The sintered alloys have a layered structure of grains oriented perpendicular to the press axis, resulting in the anisotropic thermoelectric properties. The Seebeck coefficient of the sintered alloys increases by applying a magnetic field. The magnetic field variation of the Seebeck coefficient depends on the direction of a magnetic field. This dependence could be explained by the shape effect of grains in the sintered alloys on the thermoelectric transverse-transverse effect. The power factor of the sintered alloys is improved by applying a magnetic field, and its value reachs to 2.8× 10^-5W/cmK² at H=5kOe and T=172K.