The K-Absorption Spectra of FeS2, CoS2and NiS2

The K-absorption spectra of sulfur and metal ions in a series of transition-metal disulfides MS 2 (M=Fe, Co, Ni) have been measured with two-crystal spectrometers. Considerable differences in the profiles are observed between the spectra of metal and sulfur ions, while the respective spectra are alike among different compounds. Consideration about the similarity and the dissimilarity in the spectral features suggests that the simple energy-band picture or the simple molecular-orbital picture is not adequate for the explanation of the observed spectra.