X-RAY-EMISSION SPECTRA AND ELECTRONIC-STRUCTURE OF CUIR2S4 AND CUIR2SE4

Measurements of X-ray emission spectra of Cu L-2,L-3 S K beta(1,3) S L -2,L-3 and Ir N-6,N-7 in CuIr2S4 and CuIr2Se4 have been performed. The se measurements probe the partial Cu 3d 4s, S 3p, S 3s 3d and Ir 5d de nsity of states, respectively, in the valence band. The excitation ene rgy dependence of the Cu L-2,L-3 X-ray emission (XES) in CuIr2S4 and C uIr2Se4 has been measured using tunable synchrotron radiation. These m easurements enabled us to obtain Cu L-3 XES free from overlapping Cu L -2 XES and high-energy satellites. These spectra reproduce the distrib ution of Cu 3d-states in the valence band. X-ray emission spectra of c onstituents atoms of CuIr2S4 and CuIr2Se, were adjusted to the binding energy scale using XPS binding energies of core levels and compared w ith band structure calculations and valence band spectra obtained by U PS and XPS. From these measurements one concludes that Cu 3d-states ar e less mixed with Ir Sd-states in CuIr2Se4 and their contribution to t he density of states at the Fermi level is smaller than that of CuIr2S 4. (C) 1998 Published by Elsevier Science Ltd.