Transport properties of rapid solidified Fe-Si-Mn-Cu thermoelectric alloys

Manganese and cooper doped FeSi2 and Fe2Si5 alloys were prepared by a rapid solidification technique. X-ray diffraction analysis showed that the as-so lidified FeSi2 alloy is composed of alpha-Fe2Si5 and epsilon-FeSi phases, w hile only the alpha-Fe2Si5 phase exists in the as-solidified Fe2Si5 alloy. The semiconducting phase beta-FeSi2 has not been found in the as-solidified structures but was obtained after annealing for 21 h at 800 degrees C for both alloys. It was found that the excess silicon over the stoichiometric s ilicon content of the beta-FeSi2 phase could improve the transport properti es of the materials. (C) 2000 Elsevier Science S.A. All rights reserved.