First-principles calculations of the interaction between hydrogen and 3d alloying atom in nickel

• Published in: Journal of nuclear materials 2015-10, Vol.465, p.254-259
• Main Authors: Liu, Wenguan, Qian, Yuan, Zhang, Dongxun, Liu, Wei, Han, Han
• Format: Article
• Language: English
• Subjects: Alloying; Attraction; First-principles; Hydrogen; Interstitials; Mathematical analysis; Nickel; Nickel base alloys; Three dimensional; Transition metal
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2015.06.001

Knowledge of the behavior of hydrogen (H) in Ni-based alloy is essential for the prediction of Tritium behavior in Molten Salt Reactor. First-principles calculations were performed to investigate the interaction between H and 3d transition metal (TM) alloying atom in Ni-based alloy. H prefers the octahedral interstitial site to the tetrahedral interstitial site energetically. Most of the 3d TM elements (except Zn) attract H. The attraction to H in the Ni–TM–H system can be mainly attributed to the differences in electronegativity. With the large electronegativity, H and Ni gain electrons from the other TM elements, resulting in the enhanced Ni–H bonds which are the source of the attraction to H in the Ni–TM–H system. The obviously covalent-like Cr–H and Co–H bindings are also beneficial to the attraction to H. On the other hand, the repulsion to H in the Ni–Zn–H system is due to the stable electronic configuration of Zn. We mainly utilize the results calculated in 32-atom supercell which corresponds to the case of a relatively high concentration of hydrogen. Our results are in good agreement with the experimental ones.