Early stage oxidation of Ni–Cr binary alloy (1 1 1), (1 1 0) and (1 0 0) surfaces: A combined density functional and quantum chemical molecular dynamics study

Abstract

First-principles and tight-binding quantum chemical molecular dynamics were used in this study. The chemisorption energies of O and OH on the Ni–Cr (110) surface are lower than those of other surfaces. The oxygen 2p orbitals hybridise with Ni 3d, 4s and small amounts of p orbitals for the (100) surface while Ni p orbitals have no contribution for the (110) surface, which might reduce the adsorption energy. Additionally, oxygen acquires the maximum depth into the Ni–Cr (110) surface. Applied strain increases the oxygen diffusivity. This study reveals that the Ni–Cr (110) surface is easier for oxygen diffusion accordingly oxidation accelerates.