XPS SPECTRA AND THE ELECTRONIC-STRUCTURE OF CACU AND CAAG ALLOYS

X-ray photoelectron and ultraviolet-photoemission measurements have be en made on Ca10Cu90 and Ca10Ag90 alloys. The core-level XPS spectra of Ca show strong satellites which are discussed in terms of the core-ho le screening effects. It is suggested that these spectra are due to th e mixing of d0-d1-, and d2-configurations of calcium in the final stat e and that bandlike effects are important. In the case of the x-ray-ph otoemission valence band only small differences have been observed bet ween the alloy and the noble metal, whereas for ultraviolet-photoemiss ion valence bands the corresponding changes are more pronounced. The e nergy shifts of the x-ray-photoemission valence bands are attributed t o the enhancement of the p partial density of states just below the Fe rmi level in the case of the alloy. Also, linear-muffin-tin-orbital ba nd calculations have been performed for the CaCu5 compound by using a superlattice with and without the Ca 2p core hole. When the core hole is created, the weight of the Ca 3d local partial density of states is increased at the Fermi level, whereas the Cu 3d band remains almost u n changed.