A model to partition the constituent element’s atomic energy in TiC crystal and to characterize the interface properties of α-Ti(0001)/TiC(111)

Abstract

A periodic slab model was proposed to characterize the TiC(111)/α-Ti(0001) interface properties. The model provides an effective method to partition the total energy of TiC crystalline into its constituent element’s atomic energy by constructing a periodic TiC(111)/α-Ti(0001) interface structure with a specific atomic stacking sequence on the interface. The calculation result shows that Ti and C atom possess −116.65009 Ry and −12.06893 Ry in TiC crystal respectively, which is in good agreement with the TiC total energy of −128.71901 Ry, indicating a satisfactory accuracy better than ~10−4 Ry. The information of the constituent element’s atomic energy provides a direct solution to quantitatively characterize TiC(111) surface energy, or rather, the surface energy on an arbitrary crystallographic plane of TiC crystal. The calculated Ti- and C-terminated surface energies on TiC(111) surface are −0.154 J/m2 and 8.014 J/m2 respectively. Under the atomic configuration in the present periodic model, the Ti-Ti and Ti-C interface energies were calculated to be −1.705 J/m2 and −1.891 J/m2, respectively. The investigation on the ideal work of adhesion indicated that the Ti-Ti interface is the most vulnerable region in the TiC(111)/α-Ti(0001) interface structure on account of the weaker metallic bonding between the Ti-Ti atomic layers.