Atomistic insights into interactions between oxygen and α–Zr (101-1) surface

• Main Authors: Zhixiao Liu, Wangyu Hu, Hiuqiu Deng
• Format: Article
• Language: English
• Published: Elsevier 2021-06-01
• Series: Nuclear Materials and Energy
• Subjects: Zr-based cladding material; Surface oxidization; O2 dissociation; First-principles approach
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352179121000582

The oxidation corrosion is a crucial challenge for zirconium (Zr) alloys as cladding materials in fission power reactors. In the present study, a first-principles approach is employed for understanding behaviors of oxygen adsorbed on the Zr (101-1) surface. It is found that the Zr substrate is reactive to O species. Electrons in the 4d band of the metallic substrate tend to migrate to antibonding orbitals of the adsorbed O2 molecule, leading to breaking the O-O bond and releasing energy. Several diffusion paths for an adsorbed O atom migrating to the subsurface interstitial site are proposed. It is found that the lowest diffusion barrier is only 0.08 eV. Therefore, it can be inferred that the Zr (101-1) surface suffers fast oxidation kinetics.