Improved Finnis-Sinclair potential for vanadium-rich V-Ti-Cr ternary alloys

We have developed an improved Finnis-Sinclair (IFS) potential for vanadium-rich V-Ti-Cr random alloys with body-centred cubic structure. An extra exponential term is added to the original FS potential to enhance the repulsive interaction. The IFS potential is fitted to experimental crystal structure, cohesive energy and elastic constants of pure metals (V, Ti and Cr) and theoretical data of binary alloys (V15Ti, V15Cr and Ti8Cr8). The good agreement of the predicted formation energies of mono-vacancy and self-interstitial of octahedral interstitial site, tetrahedral interstitial site, <111>-dumbbell, <110>-dumbbell, and <100>-dumbbell with available experimental and theoretical data confirms the validity of our IFS potential in pure V. Furthermore, the agreement of elastic properties and defect properties of typical alloy (V-4Ti-4Cr) with experimental or DFT data also support the applicability of the IFS potential in V-rich ternary V-Ti-Cr alloys. Finally, this work also provides a reference to develop empirical potentials for other ternary alloys.