Theoretical investigation of the ELNES of transition metal carbides for the extraction of structural and bonding information - art. no. 245105

We present the results of theoretical modeling studies of the electron ener gy loss near-edge structure (ELNES) of Group-IVA (Ti, Zr, Hf) and Group-VA (V, Nb, Ta) transition-metal carbides exhibiting a cubic NaCl structure. Ca lculations of the unoccupied densities of states at both metal and nonmetal sites have been performed using both multiple scattering (MS) and full lin earized-augmented-plane-wave (FLAPW) band-structure calculations. The effec ts of self-consistency and the inclusion of the core hole produced during t he ELNES excitation process have been investigated for the case of the MS c alculations, while the size of the basis set and the effect of charge trans fer have been examined for the case of the FLAPW calculations. The results are compared to high-energy-resolution ELNES measurements. We demonstrate t he sensitivity of ELNES features to quantities such as the lattice paramete r, chemical composition, and stoichiometry.