XPS study of the sulphur 2p spectra of pyrite

The surface core level shifts have been measured and interpreted for cleaved FeS2{1 0 0}. A new feature has been observed at about 2.0 eV from the S 2p bulk line on its low binding energy side. This small peak is the most surface sensitive component. The origin of this feature is thought to be the breakage of sulphur–sulphur bonds. The strongest surface peak is ascribed to the fracture of the Fe–S bond. An estimate for the effective attenuation lengths of photoelectrons in pyrite at kinetic energies 40, 180 and 610 eV supports the interpretation of the features.