VALENCE BAND SPECTRA OF BaCo1−xNixS2

The band properties of the quasi two-dimensional transition metal sulphide alloy system BaCo 1 − x Ni x S 2 ( x =0, 0.1, 0.2, 0.5, 1.0) have been studied by X-ray photoelectron, X-ray absorption and X-ray fluorescence spectroscopy with tunable synchrotron radiation. It is found that the metallic character of the BaCo 1 − x Ni x S 2 system increases with x in accordance with the results of transport property measurements. The S L 2,3 X-ray emission spectra show an excitation energy dependence which allowed separate mapping of the distribution of S(2) and S(1)+S(2) 3s3d partial density of states.