Properties and self-adsorptions for ZrC low-index surfaces: A first-principles study

ZrC ceramic exhibits a wide range of surface applications such as nuclear fuel cladding, prompting intensive research on its surface properties and surface adsorptions. Combining available theoretical calculations and experimental results, the surface properties including surface energetics and surface relaxations are described and compared in detail. During the process, from typical values to possible ranges, then introducing a unified description variable, three general and progressive methods are employed to evaluate the surface energy for each low-index surface of ZrC. This work also systematically analyzes the adsorption energy trend of the C or Zr adatom on each low-index surface and points out the cause of nuance for configurations with similar adsorption energies on the {100} surface. The insights are revealed that surface C atoms dominate the {100} and {110} surface adsorptions, and the {111} plane tends to be spontaneously terminated by the Zr atomic layer. Finally, combined with the thermodynamic analysis, the findings of diatomic and tetratomic adsorptions and ensuing migrations on the most stable {100} plane indicate that the growth of ZrC{100} depends on a cluster-dominated mechanism.