ELECTRONIC-STRUCTURE OF CENI1-XPDXSN AND LAMSN (M=NI,CU,PD)

The electronic structure of CeNi1-xPdxSn has been studied by photoemis sion spectroscopy. CeNiSn belongs to the class of Kondo insulating mat erials. The gap formed at the Fermi level is strongly suppressed by su bstituting Pd for Ni. The x-ray photoemission spectroscopy (XPS) valen ce band spectra can be compared with ab initio electronic-structure ca lculations using the linearized muffin-tin orbital (LMTO) method. We h ave found a small indirect gap and a low density of states at the Ferm i energy for CePdSn. The 3d XPS spectra and LMTO calculations indicate a strong hybridization of the f orbitals with conduction band and the interatomic hybridization which causes the large charge transfer betw een atoms. We have also observed the correlation between the electroni c structure near Fermi energy and the crystallographic properties of t he alloyed CeNiSn. We also present the electronic structures of LaNiSn , LaCuSn, and LaPdSn. These compounds are good reference for CeNiSn. A t Fermi energy a relatively low density of states is found, for LaCuSn an indirect gap is formed. The metallic samples show a relatively hig h resistivity at room temperature, the largest for LaCuSn,which demons trates the influence of the gap on the electric transport properties.