Environment-dependent nanomorphology of TiN: the influence of surface vacancies

In this work, we present density-functional theory calculations to investigate the surface properties of TiN as a function of surface orientation and termination, as well as the influence of surface defects for various surface defect concentrations. We calculate both the surface energies (including vacancy formation) as a function of the nitrogen chemical potential, and plot the first-principles derived equilibrium crystal shape (ECS) under different growth conditions. We find that surface defects can considerably change the derived ECS of TiN (especially under nitrogen-lean conditions), highlighting the importance of surface defect consideration in modeling nanoparticle morphology.