Study of the microstructure influence on the transport properties of Bi86.5Sb13.5 polycrystalline alloy

This study is focused on the investigation of the transport properties of B i86.5Sb13.5 polycrystalline alloys. Bulk materials were prepared by cold pr essing ultrafine powders of alloy and by annealing the resulting pellets, S pecial care was taken to avoid contamination of the powders. Starting with powders of average grain size of 0.06 mum bulk semi-conducting sample with mean grain size respectively of 0.1, 0.8, 2.5 and 200 mum were obtained. Th e influence of the grain size on both electrical resistivity, thermal condu ctivity, thermoelectric power, thermoelectric figure of merit is presented within the range 80-330 K. The thermoelectric properties are discussed and compared with those of single crystals presented in previous studies. (C) 2 001 Elsevier Science Ltd. All rights reserved.