INTERPRETATION OF ESCA SPECTRA FOR NONSTOICHIOMETRIC TITANIUM CARBIDES ON THE BASIS OF MO-LCAO CALCULATIONS

The results of electron structure calculations for the single clusters TiC620-, TiC5□16-, TiC4□212-, TiC3□38-, TiC5□16.64-, TiC4□213.32-; and double clusters Ti2C1032-, Ti2C8□224-, Ti2C10□32.72- and Ti2C8□224.80- by the semi-empirical Mulliken-Wolfsberg-Helmholtz method with self-consistency of charges and configurations are given. The data obtained are compared with measurements of the Ti 2p-level binding energies and X-ray photoelectron valence band spectra for TiCx(x = 0.86-0.97). The variation of the metal atom charge in the limits of the homogeneity region for TiC and the appearance of this effect as a chemical shift of the Ti 2p-level are discussed. A special set of cluster calculations was performed to check the possibility of Ti valency variation in the homogeneity region of TiCx. © 1974.