کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1273201 1497487 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ab initio calculation of NbH phases with low H compositions
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Ab initio calculation of NbH phases with low H compositions
چکیده انگلیسی


• BCC NbHx phase with H at tetrahedral site is energetically more favorable.
• B, G, E, and G/B values of BCC NbHx increase with H concentration.
• BCC(T) NbHx phases remain ductile when 0 ≤ x ≤ 0.5.
• H location has an important effect on elastic anisotropy.
• Calculated results agree well with experimental observations in literature.

Ab initio calculation shows that the BCC NbHx (0 ≤ x ≤ 0.5) structure with H at tetrahedral(T) site is the most thermodynamically stable one among all the BCC, FCC, and HCP phases, and its negative heat of formation decreases linearly with the increase of H composition. Calculation also reveals that the elastic moduli of BCC(T) NbHx phases all increase with the increase of H composition, and the BCC(T) NbHx phases remain ductile within the studied composition range (0 ≤ x ≤ 0.5). Moreover, it is found that the percentage anisotropy in shear (AG) and the universal anisotropic parameter (AU) are all appropriate to describe the elastic anisotropy of NbH phases, and that H location should play an important role in elastic anisotropy. The fundamental mechanism of various properties is deeply understood by means of electronic structures, and the present results agree well with experimental investigations in the literature.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Hydrogen Energy - Volume 39, Issue 22, 24 July 2014, Pages 11798–11806
نویسندگان
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