Dynamics and Thermodynamics of a Novel Phase of NaAlH[subscript 4]
Name
Wood-2009-Dynamics and Thermodynamics of a Novel Phase of NaAlH4.pdf
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Author(s) •
Wood, Brandon C.
Marzari, Nicola
Date Issued
October 2009
Journal
Physical Review Letters
Publisher
American Physical Society
Citation
Wood, Brandon C., and Nicola Marzari. “Dynamics and Thermodynamics of a Novel Phase of NaAlH4.” Physical Review Letters 103.18 (2009): 185901. © 2009 The American Physical Society
Version
Final published version
Abstract
We characterize a novel orthorhombic phase (γ) of NaAlH[subscript 4], discovered using first-principles molecular dynamics, and discuss its relevance to the dehydrogenation mechanism. This phase is close in energy to the known low-temperature structure and becomes the stabler phase above 320 K, thanks to a larger vibrational entropy associated with AlH[subscript 4] rotational modes. The structural similarity of γ-NaAlH[subscript 4] to α-Na[subscript 3]AlH[subscript 6] suggests it acts as a key intermediate during hydrogen release. Findings are consistent with recent experiments recording an unknown phase during dehydrogenation.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
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DOI of Published Version
http://dx.doi.org/10.1103/PhysRevLett.103.185901