Synthesis and characterization of micron-size pyrite crystals

Mixed solvent of ethanol and water using FeSO4?7H2O and (NH2)2CS as precursors with polyvinylpyrrolidone as surfactant was used to synthesize cubic FeS2(pyrite) crystals. Crystalline phase and surface morphologies of the crystals were characterized by X-ray diffraction and scanning electron microscopy, respectively. Volume ratio of solvent, reaction temperature, reaction time, and sulfur source were found to be the key parameters for the formation of pure pyrite crystals. Optimal micron-size pyrite crystals were successfully grown from a mixed solvent of ethanol and water with a volume ratio of 3:2, heated to a reaction temperature of 180 ?C, and maintained for 36 h with thiourea as the sulfur source.