کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9803192 1516463 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nature of the chemical bond in complex hydrides, NaAlH4, LiAlH4, LiBH4 and LiNH2
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Nature of the chemical bond in complex hydrides, NaAlH4, LiAlH4, LiBH4 and LiNH2
چکیده انگلیسی
The most stable crystal structures of complex hydrides, MXHn (NaAlH4, LiAlH4, LiBH4 and LiNH2) were simulated by the plane-wave pseudopotential method. The local chemical bonds between constituent ions were simulated using the DV-Xα molecular orbital method. As a result, it was found that the covalent interaction is operating between X and H ions to form a XHn ion in MXHn. In addition, the ionic interaction is operating between M and XHn ions through the charge transfer from M to XHn ions. On the basis of this understanding of the nature of the chemical bond between ions, a phase stability diagram of complex hydrides was proposed using two parameters. One is the bond energy of XH diatomic molecules and the other is electronegativity difference, ΔΦX M, between M and X ions. The calculated stability change by doping into NaAlH4 could by explained qualitatively following this diagram. This diagram will provide us a clue to the modification of hydrides to lower the hydrogen decomposition temperature.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volumes 404–406, 8 December 2005, Pages 185-190
نویسندگان
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