A resonant-photoemission study of YNi2B2C

Valence level photoemission measurements of the normal-state electronic structure of the new boro-carbide intermetallic superconductor YNi2B2C are presented. The behaviour of the Ni-dominated valence band peak at 1.4 eV binding energy and the states at EF across the Ni3p absorption threshold clearly indicate significant Ni3d contributions at these energies. In addition, the transfer of spectral weight from the main Ni3d valence band to a two-hole bound-state satellite at ∼ 8 eV signals the role played by electron correlation in these materials. The peak in the DOS predicted to lie at EF in band structure calculations is not observed in the experiment, possibly also due to the effects of electron correlation. (orig.)