First-principles study of bubble formation and cohesion properties of hydrogen at Fe/W interfaces

• Published in: International journal of hydrogen energy 2019-10, Vol.44 (48), p.26469-26476
• Main Authors: Wang, Qian, Du, Guoping, Chen, Nan, Jiang, Changshuang
• Format: Article
• Language: English
• Subjects: Fe/W interfaces; First-principles study; Hydrogen solubility; Interface cohesion; Thermodynamic stability
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.08.070

First-principles study is used to comparatively investigate the mechanism of bubble formation of hydrogen at Fe/W interfaces and the effects of H on interface cohesion. It is found that hydrogen at interfacial sites has a negative binding energy, which is quite different from W and Fe bulks with interstitial hydrogen. The hydrogen solubility of the interface is bigger than W and Fe bulks with the increasing temperature, predicting that the Fe/W interface can more easily trap hydrogen and rapidly form bubbles. In addition, we also reveal the sites of hydrogen have an important role on cohesion properties of Fe/W interface, and that the obvious increase of interface strength and stability have been found in the locations of hydrogen relatively far away the center between Fe and W interface layers. The derived results are discussed extensively through comparing with available observations in the literature, and could give a deep understanding of hydrogen at Fe/W interfaces. •Hydrogen at Fe/W interface has a negative binding energy.•The hydrogen solubility of Fe/W interface is bigger than W and Fe bulks with the increasing temperature.•The location of hydrogen has an important role on cohesion properties of Fe/W interface.•Our simulations agree well with similar experimental observations in the literature.