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
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
پیش نمایش صفحه اول مقاله

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, ÎΦX 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 404â406, 8 December 2005, Pages 185-190
Journal: Journal of Alloys and Compounds - Volumes 404â406, 8 December 2005, Pages 185-190
نویسندگان
M. Yoshino, K. Komiya, Y. Takahashi, Y. Shinzato, H. Yukawa, M. Morinaga,