کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1625974 1516429 2007 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ab initio prediction of high-pressure structural phase transition in BaH2
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Ab initio prediction of high-pressure structural phase transition in BaH2
چکیده انگلیسی
We have performed ab initio electronic structure calculations to calculate the structural properties and high-pressure phase transition in Barium dihydride (BaH2). Our results show that BaH2 crystallizes the orthorhombic phase (CoSi2-type structure) with Pnma space group at ambient conditions. A phase transition to the hexagonal (Ni2In-type structure) with P63/mmc space group is found at pressure around 4 GPa. At the phase transition, the coordination number of hydrogen increases from 9 to 11 and the average bond length of BaH increases. The results show a band gap of 2.9 eV for orthorhombic and 1.8 eV for hexagonal phase. In addition, it was also found that more energy is required to desorb hydrogen atom from high-pressure phase as compared to ambient phase.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volumes 446–447, 31 October 2007, Pages 405-408
نویسندگان
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