from the conferences organized by TANGER Ltd.
Titanium nitride (TiN) is largely applied as protective nanolayer of medical titanium implants due to its significant positive influence on the surface properties such as friction and corrosion resistance. During the process of its phase formation, occurrence of the point defects is probable and can potentially affect various material properties, e.g. change the lattice parameters. The surface energies of 8 crystallographic planes and effects of nitrogen vacancies on the lattice parameter in rock salt-like structure of TiN (δ-TiN) were studied using ab-initio method of density functional theory (DFT) with the generalized gradient approximation functional (GGA) as parametrized by Perdew, Burke and Ernzerhof (PBE). TiN supercell with 64 atomic positions was used for the calculation of defects influence and the results are thoroughly discussed in the context of available theoretical and experimental literature data. The linear decrease of lattice parameter with the increasing presence of nitrogen vacancies up to ca. 80 % was observed. The surface energy of (100) crystallographic plane is two times lower (1.499 J/m2) than for the rest of the studied planes.
Keywords: Titanium nitride, TiNx, ab initio simulation, density functional theory, DFT, vacancies, lattice parameter, surface energy© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.