Auger electron spectroscopy--electron energy-loss spectroscopy--low-energy electron diffraction study of a V6C5(100) surface

The surface properties of (100) oriented substoichiometric vanadium carbide V6C5 were examined by electron spectroscopy and low-energy electron diffraction (LEED) observation. The electron energy-loss spectroscopy (EELS) spectra for a clean surface of the crystal showed similar features to those of a TiC(100) except for the loss region of less than 10 eV. In the LEED experiment, however, rather complicated patterns appeared contrary to the case of TiC(100), which indicated only fundamental lattice structure. The displacement of LEED spots with the energy variation of primary electron suggested that the surface was formed with two different kinds of facet planes. The carbides in general are inactive against common gases, while reactive particles such as oxygen interact with these materials. The irradiation of atomic hydrogen onto the specimen, however, causes no significant changes either in the compositional ratio of vanadium versus carbon or in LEED patterns. In the EELS spectra, by atomic hydrogen irradiation, the 3-eV loss peak disappeared, while a new peak near the 10-eV loss peak appeared, suggesting that atomic hydrogen could interact with this surface