Energy-band structure of NbC studied with angle-resolved photoelectron spectroscopy

The (100) face of NbC0.83 has been studied using angle-resolved photoelectron spectroscopy and synchrotron radiation as the excitation source. The experimental results are compared with the theoretical energy-band structure calculated for stoichiometric NbC using the linear augmented-plane-wave method. A good agreement between theory and experiment is found for the main structures in the experimental spectra. The origin of the experimental features that cannot be explained by the calculated energy bands is discussed in terms of surface and vacancy-induced effects. A resonant enhancement of the emission close to the Fermi energy at photon energies above the Nb 4p threshold is presented and discussed.