Semiconducting properties of pyrite

It is well known that Pyrite associated with Black Ore induces the severest difficulty among other constituents in the flotation process in mineral dressing. One of the possible reasons for this difficulty is related to its semiconducting properties which may affect surface conditions. We present here a study of the semiconducting properties of pyrite. Our calculations of the energy gap at various temperatures are shown to be in very good agreement with the experimental data. The Penn gap calculated using the Grimes-Cowley modification [1] of the Penn model has been shown to agree very well with the reflectivity data of Horita [2]. Using the Clausius-Mossotti relation, we calculate the electronic polarizability for pyrite. Also evaluated are the pressure and lattice parameter dependence of the energy gap. We predict the temperature of decomposition of natural pyrite in inert atmosphere from Mössbauer studies.