First-principles calculations of hydrogen in perfect WFe and WFeNb crystals. (January 2017)

• Record Type: Journal Article
• Authors: Chen, L.; Wang, Q.; Xiong, L.; Gong, H.R.
• Is Part Of: Solid state communications. Volume 249(2017)
• Page Start: 24
• Page End: 29
• Publication Date: 2017-01
• Subjects: A. WFeH phases -- A. WFeNbH phases -- C. Mechanical properties -- D. Diffusion of H; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2016.10.013
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: First principles calculations reveal that the addition Nb in WFeH phases changes the preferred site, i.e., WFeH(O2) → WFeNbH(T), and the addition of Nb can decrease the structural stability of WFeNbH(T) phase. It is also shown that Nb-H bond should have a stronger chemical bonding than W-H bond and Fe-H bond in WFeNbH phases when the bond length is bigger than 1.8 Å, which account for favorable mechanical properties of WFeNbH phases. Additionally, the most probable paths of H diffusion in WFe and WFeNb phases are calculated. The values of barriers denote that the addition of Nb in WFeH phases can result in H diffusing rapidly. The calculated results are in good agreements with experimental observations in the literature, and are discussed in terms of electronic structures and bond characteristics. Highlights: The effects of Nb on structural stability of WFeNb phases are revealed by first principles calculations. The comparison of H on mechanical properties in W16 H, W8 Fe8 H and W8 Fe7 NbH phases is investigated in the present study. A comparative study of H diffusion in various W, W8 Fe8 and W8 Fe7 Nb phases is conducted in the present calculation.