大块铜中金属空位与氢相互作用的热力学分析。

Thermodynamic analysis of the interaction between metal vacancies and hydrogen in bulk Cu.

机构信息

Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.

Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK.

出版信息

Phys Chem Chem Phys. 2023 Mar 29;25(13):9168-9175. doi: 10.1039/d3cp00085k.

DOI:10.1039/d3cp00085k

PMID:36943172

Abstract

Using grand canonical thermodynamic analysis with inputs from DFT calculations we calculated equilibrium molar fractions of copper vacancies (V), H interstitials (H) and their complexes in bulk Cu in a wide range of temperature and hydrogen pressure values. The results show that the equilibrium molar fractions of both V and H are low in most conditions of interest, in good agreement with available experimental data. Although H-V complexes have significantly lower formation energies than the isolated defects, the low molar fraction of H is predicted to have little impact on the rise in vacancy molar fraction for external hydrogen pressures below 100 bar. Only at relatively high hydrogen pressures exceeding 10 kbar in the presence of Cu vacancies, the H molar fraction was found to reach the same order of magnitude as the molar fraction of vacancies. These results put thermodynamic limits on the hydrogen-induced vacancy clustering and void formation in bulk Cu.

摘要

利用巨正则热力学分析和 DFT 计算的输入，我们计算了在较宽的温度和氢压范围内，体相 Cu 中铜空位 (V)、H 间隙原子 (H)及其复合物的平衡摩尔分数。结果表明，在大多数感兴趣的条件下，V 和 H 的平衡摩尔分数都较低，与可用的实验数据吻合较好。尽管 H-V 复合物的形成能明显低于孤立缺陷，但在外部氢压低于 100 bar 时，H 的低摩尔分数预计对空位摩尔分数的升高影响不大。只有在存在铜空位且氢压相对较高（超过 10 kbar）的情况下，H 的摩尔分数才会达到与空位摩尔分数相同的数量级。这些结果对体相 Cu 中氢诱导的空位聚集和空穴形成施加了热力学限制。