Ultraviolet-photoemission- and energy-loss-spectroscopy study ofNbNxandZrNx

Reflection electron-energy-loss spectroscopy (ELS) and angle-integrated ultraviolet-photoemission spectroscopy (UPS) have been used to study the electronic properties of the mononitrides of Nb and Zr. Polycrystalline, high-purity transition-metal foils were nitrided by heating in a nitrogen atmosphere. ELS was used to examine collective oscillations ("plasmons") of the valence electrons and the one-electron core-level thresholds, while UPS at photon energies of 16.8 and 21.2 eV was used to probe the occupied-valence-band density of states. The results provide good qualitative support for existing band-structure and density-of-states calculations for NbN. Strong similarities are found between the present results and those reported previously for $\mathrm{V}{\mathrm{N}}_x$.