Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9804137 | Journal of Alloys and Compounds | 2005 | 5 Pages |
Abstract
The structure of magnesium alanate, Mg(AlH4)2, has been examined in detail by combined powder synchrotron X-ray and neutron diffraction. The space group is confirmed to be P3¯m1 with unit cell dimensions of a = 5.2084(3) Ã
and c = 5.8392(5)Â Ã
at 8Â K, a = 5.20309(12)Â Ã
and c = 5.8400(2)Â Ã
at 111Â K and a = 5.1949(2)Â Ã
and c = 5.8537(2)Â Ã
at 295Â K. The structure consists of isolated and slightly distorted AlH4â tetrahedra that are connected via six-coordinated Mg atoms in a distorted octahedral geometry, resulting in a sheet-like structure along the crystallographic c-axis. The distortion of the AlH4â tetrahedra decreases with increasing temperature, whereas, the opposite is the case for the MgH6 octahedra. The Al-H distances are 1.606(10)-1.634(4)Â Ã
, 1.602(10)-1.682(3)Â Ã
and 1.561(12)-1.672(4)Â Ã
at 8, 111 and 295Â K, respectively.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
A. Fossdal, H.W. Brinks, M. Fichtner, B.C. Hauback,