X-ray photoelectron spectra of 3d transition metal pyrites

Photoelectron spectra of the synthetic compounds FeS2, CoS2, NiS2, MnSe2, CoSe2, and NiSe2 and of a natural crystal of MnS2, all with the pyrite structure, are reported. The sulfur 3s and selenium 4s contributions are split into peaks for bonding and antibonding orbitals due to the covalent bonding in the molecular anion pairs. The difference in lineshape of the peaks for the bonding and antibonding orbitals is attributed to vibronic effects. The metal 2p32 spectra show the effects of multiplet splitting and satellites due to shake-up or shake-off processes. The valence band spectra consist of slightly overlapping contributions of anion p and metal 3d electrons. The metal 3d spectrum of FeS2 has a single strong peak of width 0.9 eV. The 3d spectra of the other compounds show structure due to several final state configurations.