The thermoelectric properties of FeS2

摘要

Pyrite (FeS2) whose Mohs hardness is the largest among all the sulphides is a naturally occurring mineral and is also known as "fool's gold" for its colour and brightness. It has a cubic symmetry of NaCl-like crystal structure where the Fe atoms occupy Na-sites while S2 molecules occupy the Cl-sites. Recently, attention has been paid to the pyrite as a candidate for effective solar energy conversion because it is a semiconductor with a band gap of 0.9 eV On the other hand pyrite is also considered as a material for an efficient thermoelectric generator whose Seebeck coefficient reaches several hundred pi V/K at around room temperature [1-3]. From the viewpoint of future energy problems, it is important to study the thermoelectric conversion materials because the conversion of thermal energy into electric energy meets the need when the available temperature difference is comparatively small. The thermoelectric materials are characterized by the figure of merit Z, which signifies the conversion efficiency of thermal energy into electric energy. Z is defined by the following equation.