Magnesium silicide

• Dimagnesiumsilicid
• Magnesium silicide

Slate blue solid

Fixed

1.94 g · cm -3

1085 ° C

Reacts violently with water

Risk

Template: Infobox chemical / molecular formula search available

Magnesium silicide is an inorganic chemical compound of magnesium selected from the group of silicides.

Production and representation

Magnesium silicide may be obtained by reaction of magnesium with silicon.

Also possible is the preparation by reaction of silica with magnesium.

Phase-pure magnesium silicide can be formed from magnesium and silicon with the aid of the SPS method.

Properties

Magnesium silicide is a solid with hard and very brittle, slate blue crystals. It represents a Zintl phase and was first mentioned in 1858 by Friedrich Wöhler. More specifically, the compound was first investigated by Lebeau and Bossuet in 1908, who managed to Reinstdarstellung of magnesium silicide. With water, it reacts violently extremely flammable gases. About 723 K, the compound reacts with oxygen in air to form magnesium oxide and silicon. It has an anti-fluorite type crystal structure (a = 6.39 Å ) having the space group Fm3m and is an n-type semiconductor (specifically, an intrinsic semiconductor ) which is assigned to the compound semiconductors. Below 230 ° C show a brittle material behavior magnesium silicide, as also converts into a plastic. The breaking strength of the single crystals decreases with increasing temperature of 100 MPa at room temperature to 10 MPa at 630 ° C. The connection is resistant to alkalis, acids decompose the compound to form silicon hydride compounds ( silanes) and hydrogen. Thus is formed upon contact with hydrochloric acid magnesium chloride and mono-silane.

Use

Magnesium silicide is used for the manufacture of silanes and to improve properties of magnesium and aluminum alloys.