First principles study of oxidation resistance of atomically flat Cu(111) surface*

Copper is one of the important materials used in modern technology and industries, but oxidation of copper deteriorates its application in nanotechnology. Our recent first principles total-energy calculations based on density functional theory is used to investigate the oxidation resistance of atomically flat Cu(111) surface. The exchange-correlation energy is described by the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) and projected augmented wave (PAW) method is employed. Our results show that atomically flat Cu(111) without multi-atomic steps is oxidation resistant. The energy barrier for oxygen penetrating flat surface and mono-atomic step is very high in comparison to multi-atomic steps. Also, incremental oxygen adsorption energy for the fcc site of the flat surface becomes positive and oxygen resistant above the oxygen coverage of 50%. These calculated results are consistent with the recent experimental finding.