5688. Magnesium Silicide

Nomenclature

CAS number: 22831-39-6
Mg2Si; mol wt 76.70.
Mg 63.38%, Si 36.62%.

Description and references

Prepd by heating finely powdered Mg and Si in a proportion of 20 to 6: Gire, Compt. Rend. 196, 1404 (1933), C.A. 27, 3678 (1933); Winkler, Helv. Phys. Acta 28, 633 (1955), C.A. 50, 6908c (1956). Prepn and conversion to silanes: Emeleus, Maddock, J. Chem. Soc. 1946, 1131.

Properties

Slate-blue, cubic crystals. d420 ≈2.0. mp 1085°. Dec at 550° in vacuo yielding Mg3Si2. Heat of formation: 18.5 cal/mol. Dec by water, HCl. Dangerous when wet.

Use

In semiconductor research. Has been used to build Mg-Si rectifiers.