Magnesium sulfide

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Magnesium sulfide
Magnesium sulfide crystal structure
Names
Other names
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.597
EC Number 234-771-1
Properties
MgS
Molar mass 56.38 g/mol
Appearance white to reddish brown powder
Density 2.84 g/cm3
Melting point 2,000 °C (3,630 °F; 2,270 K) approx.
decomposes
Structure
Halite (cubic), cF8
Fm3m, No. 225
cubic
Thermochemistry
45.6 J/mol K
50.3 J/mol K
-347 kJ/mol
Related compounds
Other anions
Magnesium oxide
Other cations
Calcium sulfide
Strontium sulfide
Barium sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Magnesium sulfide is an inorganic compound with the formula MgS. It is a white crystalline material but often is encountered in an impure form that is brown and non-crystalline powder. It is generated industrially in the production of metallic iron.

Preparation and general properties[edit]

MgS is formed by the reaction of sulfur or hydrogen sulfide with magnesium. It crystallizes in the rock salt structure as its most stable phase, its zinc blende[1] and wurtzite[2] structures can be prepared by Molecular Beam Epitaxy. The chemical properties of MgS resemble those of related ionic sulfides such as those of sodium, barium, or calcium. It reacts with oxygen to form the corresponding sulfate, magnesium sulfate. MgS reacts with water to give hydrogen sulfide and magnesium hydroxide.[3]

Applications[edit]

In the BOS steelmaking process, sulfur is the first element to be removed. Sulfur is removed from the impure blast furnace iron by the addition of several hundred kilograms of magnesium powder by a lance. Magnesium sulfide is formed, which then floats on the molten iron and is removed.[4]

MgS is a wide band-gap direct semiconductor of interest as a blue-green emitter, a property that has been known since the early 1900s.[5] The wide-band gap property also allows the use of MgS as photo-detector for short wavelength ultraviolet light.[6]

Occurrence[edit]

Aside from being a component of some slags, MgS is a rare nonterrestial mineral niningerite detected in some meteorites. MgS is also found in the circumstellar envelopes of certain evolved carbon stars, i. e., those with C/O > 1.[7]

Safety[edit]

MgS evolves hydrogen sulfide upon contact with moisture.

References[edit]

  1. ^ Bradford, C.; O'Donnell, C. B.; Urbaszek, B.; Balocchi, A.; Morhain, C.; Prior, K. A.; Cavenett, B. C. (2000). "Growth of zinc blende MgS/ZnSe single quantum wells by molecular-beam epitaxy using ZnS as a sulphur source". Appl. Phys. Lett. 76: 3929. doi:10.1063/1.126824. 
  2. ^ Lai, Y. H.; He, Q. L.; Cheung, W. Y.; Lok, S. K.; Wong, K. S.; Ho, S. K.; Tam, K. W.; Sou, I. K. (2013). "Molecular beam epitaxy-grown wurtzite MgS thin films for solar-blind ultra-violet detection". Applied Physics Letters. 102: 171104. doi:10.1063/1.4803000. 
  3. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  4. ^ Irons, G. A.; Guthrie, R. I. L. "Kinetic aspects of magnesium desulfurization of blast furnace iron" Ironmaking and Steelmaking (1981), volume 8, pp.114-21.
  5. ^ Tiede, E. "Reindarstellung von Magnesiumsulfid und seine Phosphorescenz. I (Preparation of pure magnesium sulfide and its phosphorescence. I)" Berichte der Deutschen Chemischen Gesellschaft (1916), volume 49, pages 1745-9.
  6. ^ Hoi Lai, Ying; Cheung, Wai-Yip; Lok, Shu-Kin; Wong, George K.L.; Ho, Sut-Kam; Tam, Kam-Weng; Sou, Iam-Keong (2012). "Rocksalt MgS solar blind ultra-violet detectors". AIP Advances. 2: 012149. doi:10.1063/1.3690124. 
  7. ^ Goebel, J. H.; Moseley, S. H. (1985). "MgS Grain Component in Circumstellar Shells". Astrophysical Journal (Letters). 290: L35. Bibcode:1985ApJ...290L..35G. doi:10.1086/184437.