An electrolyte electroreflectance study of FeS₂

Abstract

We report an electrolyte electroreflectance (EER) study of synthetic pyrite FeS2 single crystals in the energy range 1-6 eV. The EER spectrum exhibits derivative-like structures in the vicinity of the interband transitions. The transition energies are determined accurately and a probable energy band structure near the Fermi level is constructed. It is proposed that FeS2 has a completely filled 3d t2g band occupied by six electrons in the low-spin configuration, separated from empty S 3p sigma * and Fe 3d eg* bands, and that the bottom of the conduction band corresponds to the S 3p sigma * antibonding states.