Magnesium aluminide is an
intermetallic compound of
magnesium
Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...
and
aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
. Common phases (molecular structures) include the beta phase (Mg
2Al
3) and the gamma phase (Mg
17Al
12), which both have
cubic
Cubic may refer to:
Science and mathematics
* Cube (algebra), "cubic" measurement
* Cube, a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex
** Cubic crystal system, a crystal system w ...
crystal structures. Magnesium aluminides are important constituents of
5XXX aluminium alloys (aluminium-magnesium) and magnesium-aluminium alloys, determining many of their engineering properties. Due to the advantage of low density and being strong, magnesium aluminide is important for aircraft engines. MgAl has also been investigated for use as a
reactant to produce
metal hydrides in
hydrogen storage
Several methods exist for storing hydrogen. These include mechanical approaches such as using high pressures and low temperatures, or employing chemical compounds that release H2 upon demand. While large amounts of hydrogen are produced by variou ...
technology. Like many intermetallics, MgAl compounds often have unusual
stoichiometries
Stoichiometry () is the relationships between the masses of reactants and products before, during, and following chemical reactions.
Stoichiometry is based on the law of conservation of mass; the total mass of reactants must equal the total mas ...
with large and complex
unit cells.
-Mg
2Al
3 is a
complex metallic alloy which crystallizes in cubic unit cell with 1168 atoms per cell. If the
Wyckoff positions were fully occupied, the structure would have 1832 atoms, but the sites are only partially occupied. The structure has very low density, and has been suggested for use in
hydrogen storage
Several methods exist for storing hydrogen. These include mechanical approaches such as using high pressures and low temperatures, or employing chemical compounds that release H2 upon demand. While large amounts of hydrogen are produced by variou ...
.
References
*
Alloys
Aluminides
Magnesium compounds
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