Valence band structures of titanium nitride and titanium carbide calculated with chemically complete clusters

Abstract

Valence band structures of TiN and TiC have been calculated by the cluster method. A chemically complete cluster (X = N or C) is used to improve termination of the cluster and electroneutrality of the Ti-N and Ti-C stoichiometric pairs. Density of states for the valence band, theoretical Ti , Ti K and X K x-ray emission spectra for TiN and TiC are presented and are in good agreement with the experimental ones. Interaction between the metal and non-metal atoms is discussed. Experimental Ti x-ray emission spectra for TiN and TiC have also been obtained in the present work, using monochromatized synchrotron radiation.

High‐resolution soft X‐ray spectral analysis in the CK region of titanium carbide using the DV‐Xα molecular orbital method

“…In the XES, TiC was represented by a main peak (denoted by b ) at 279 eV with a low‐energy small peak ( a ) at 277.5 eV and a high‐energy shoulder ( c ) around 281 eV. This spectral profile agrees with previously published data 9, 15. The spectral width of TiC (∼6 eV in full width) was narrower than that of HOPG (>15 eV), implying that the carbon atoms in TiC have an ionic character, whereas those in HOPG have a covalent character.…”

“…In the smallest Ti 6 C 7 model, the center C atom was surrounded by six 1st‐neighbor Ti atoms and six 2nd‐neighbor C atoms. In the Ti 19 C 6 model, which is the model previously calculated by Song et al 9, the center Ti atom was surrounded by six 1st‐neighbor C atoms and 18 2nd‐neighbor Ti atoms. In the Ti 14 C 19 model, the center C atom was surrounded by six 1st‐neighbor Ti atoms and 18 2nd‐neighbor C atoms.…”

“…Various metal/carbon systems, for example MC (M: Zr, Hf, V, Nb, Ta) 7, TiC 7–9, SiC 10, Ti 4 SiC 3 11, and UC 12 have been analyzed by combining soft X‐ray spectroscopy and/or the DV‐Xα method. However, the previously reported X‐ray spectral profiles occasionally appear to have a lower resolution, and the spectral simulations using the DV‐Xα method often seem to be insufficient for the high‐resolution spectral profiles.…”

In situcore-level and valence-band photoelectron spectroscopy of reactively sputtered titanium aluminum nitride films

“…The density of states for the valence band of TiN has been calculated by Neckel et al, 36 Ahuja et al, 37 and Song et al 38 The results are very similar, predicting a maximum at 5.5 eV binding energy which is mainly due to N 2p states, and an increasing density of states toward the Fermi level which is attributed mainly to Ti 3d states. The electronic structure of the wurtzite-type phase of aluminum nitride was calculated by Ruiz, Alvarez, and Alemany.…”

Origin of Low-Energy Peaks in the Ti-K XANES Spectra of SrTiO<SUB>3</SUB> and CaTiO<SUB>3</SUB>

“…Numerical integrations for dipole matrix elements were performed in the manner described in Refs. [21] and [22]. Lorentzian curves with a width (FWHM) of 2.0 eV were used to reproduce observed band shapes.…”