First Principles Study of Mechanical Properties and Electronic Structures of Vanadium-Doped TiC and TiN

The mechanical properties and electronic structures of TiC and TiN with different doping ratio of vanadium (V) are studied in this work using the first principles calculations. The simulation results show that Ti_1−xV_xN has lower formation energy than Ti_1−xV_xC, suggesting higher chemical stability of Ti_1−xV_xN. Ti_0.25V_0.75C and TiN show larger hardness than other Ti_1−xV_xC and Ti_1−xV_xN compounds. The anisotropic Young's modulus of Ti_1−xV_xC and Ti_1−xV_xN models are plotted in 3D surface constructions, and VN exhibited the strongest anisotropy. The uniaxial tensile simulation of Ti_1−xV_xC and Ti_1−xV_xN are conducted along [111] direction. The tensile strength of Ti_1−xV_xN is stronger than Ti_1−xV_xC. The tensile strength increases with the increasing of V-doping ratio. Furthermore, the electronic structures of Ti_1−xV_xC and Ti_1−xV_xN are estimated. The modeling techniques used in this work and the calculation results are helpful for systematically understanding the properties of Ti_1−xV_xC and Ti_1−xV_xN in nanoscale.