Electronic structure of CexSny compounds

We present the structural properties, the electronic structure, and the 3d and 4d X-ray photoemission (XPS) spectra for eight cerium stannides of the CexSny-type. Previous magnetic investigations showed that Ce in CeSn3, Ce2Sn5 and Ce3Sn7 has a mixed valence whereas Ce5Sn3 and Ce3Sn are known as heavy fermions. The 3d and 4d XPS spectra obtained for CexSny series indicate a mixed valence of Ce. The 3d XPS spectra and LMTO calculations indicate a strong hybridization energy Δ of the f-orbitals with conduction band. Both the quantity: hybridization energy Δ, as well as the valence of Ce, depend on the number of Ce atoms and give evidence, that the type of crystallographic structure and the number of nearest Ce-neighbors decide about the ground state properties of these compounds.