Heat capacity study of β-FeSi2 single crystals

Heat capacity of needle-like (length = 5 mm, diameter = 1 mm) beta-FeS2 single crystal grown by chemical vapor transport has been measured. Two anomalies are found; a broad deviation centered around 160 K and a clear deviation at a temperature of (approximately) 255 K. We have attempted to relate these to the anomalies previously reported in the case of the resistivity data. The transient thermoelectric effect (TTE) results lead us to the inference that the system under-goes a transition from a single carrier system to at least a two carrier system at 220 K. Our heat capacity results seem to provide further independent evidence for this transition in this system. (c) 2006 Elsevier B.V. All rights reserved.