First-principles study of the insertion and diffusion of interstitial atoms (H, C, N and O) in nickel

JOURNAL OF ALLOYS AND COMPOUNDS

卷:822

Article

David, Matthieu¹  Prillieux, Aurelien¹  Monceau, Daniel¹  Connetable, Damien¹ 

[1] UPS, CIRIMAT, ENSIACET, CNRS,INP,UMR 5085, 4 Allee Emile Monso,BP 44362, F-31030 Toulouse 4, France

关键词: nickel;    Interstitial species;    DFT;    Diffusion;    Solubility;   

DOI  :  10.1016/j.jallcom.2019.153555

来源: Elsevier

【 摘 要 】

Solubility and diffusivity of interstitials in Ni is of prime importance to understand and quantify reactivity of Ni-base structural alloys at high temperature. We thus present a first-principles study of the insertion and diffusivity of interstitial species in nickel. We put an emphasis on carbon, nitrogen and oxygen atoms and compare our results with those found for hydrogen and in the literature. The interactions with the metal and the relative stability of sites are discussed in detail in terms of phonon, electronic, elastic, magnetic properties and charge transfers. As a result, we identified one new stable interstitial position for C and N atoms, and we also showed that the tetrahedral site can be considered as unstable from an elastic standpoint for carbon. In the light of these new results, diffusion mechanisms were reviewed and diffusion coefficients were calculated. The effects of temperature on enthalpy and migration energies were investigated. We thus showed that C and N atoms on one hand, H and O atoms on the other hand, show the same behavior. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free