Low temperature resistivity studies of Fe-Cr-Sn alloys in alpha and sigma phases

Low-temperature resistivity measurements were carried out on a set of FeCrS n samples with Sn concentrations of 1, 2 and 3.5 at% and structures ranging from pure alpha-phase to heavy alpha/sigma mixing up to an almost purl sig ma-phase. Fe-57 Mossbauer spectroscopy was used to characterize the samples and to evaluate the fraction of the sigma-phase present in each. The alpha -sigma transformation is easily observed by electrical resistivity since th e thermal variations of rho are very sensitive to alpha and sigma phases. I t was observed that with increasing Sn concentration the increase of rho wi th temperature is sharper in the sigma phase, and is smaller in the alpha p hase. This is explained in terms of the role of Sn in the microstructure of FeCrSn alloys. (C) 2000 Elsevier Science S.A. All rights reserved.