The Electronic and Elastic Properties of Si Atom Doping in TiN: A First-Principles Calculation.

The elastic properties and electronic structure of interfaces in Ti-Si-N nanocomposite films were calculated using first principles based on density functional theory (DFT). The results showed that the mechanical moduli of the single-substitution interface (1Si-6N) were higher than those of the double-substitution interface and interstitial interface (1Si-4Ti4N). The single-substitution interface (1Si-6N) was revealed to be characterized as the more elastically isotropic structure in different directions, whereas the Young's moduli significantly varied in different directions in the interstitial interface (1Si-4Ti4N). The electronic structures of interfaces indicated that the structures were conductors with intersecting bands. Strongly delocalized d states of titanium and silicon ions were spread over a wide region of about 10-12 eV and were strongly hybridized with the nitrogen 2p states. The overall appearance of the calculated cross-sections of the electron density difference changed drastically. [ABSTRACT FROM AUTHOR]