Magnesium selenide is an inorganic compound with the chemical formula MgSe. It contains magnesium and selenium in a 1:1 ratio. It belongs to the II-VI family of semiconductor compounds.

Magnesium selenide
Names
Systematic IUPAC name
Magnesium selenide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.820 Edit this at Wikidata
EC Number
  • 215-201-0
UNII
  • InChI=1S/Mg.Se/q+2;-2
    Key: AZUPEYZKABXNLR-UHFFFAOYSA-N
  • [Mg+2].[Se-2]
Properties
MgSe
Molar mass 103.27 g/mol[1]
Density 4.21 g/cm3 (rock-salt)[2]
3.32 g/cm3 (zincblende)[1]
Melting point 1,290 °C; 2,350 °F; 1,560 K[1]
Band gap 3.9 eV (rock-salt) (300 K)
4.0 eV (zincblende) (300 K)
Structure
Rock-salt (cubic)
Zincblende (cubic)
Wurtzite (hexagonal)
a = 0.55 nm (rock-salt)
a = 0.59 nm (zincblende)
a = 0.415 nm, c = 0.672 nm (wurtzite)[2]
Related compounds
Other anions
Magnesium oxide
Magnesium sulfide
Magnesium telluride
Other cations
Cadmium selenide
Mercury selenide
Zinc selenide
Related compounds
Magnesium zinc selenide
Cadmium magnesium selenide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Structure

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Three crystal structures for MgSe have been experimentally characterized. The rock-salt structure is considered to be the most stable crystal structure that has been observed in bulk samples of MgSe, and a cubic lattice constant of 0.55 nm was deduced for this structure.[2] Although attempts at preparing pure zincblende MgSe have been unsuccessful,[3] the lattice constant of zincblende MgSe has been extrapolated from epitaxial thin films of zincblende MgxZn1-xSySe1-x and MgxZn1-xSe grown on gallium arsenide, the latter of which was prepared with a high magnesium content (up to 95% Mg, i.e., Mg0.95Zn0.05Se).[3][4] There is good agreement between these and other extrapolations that the lattice constant of pure zincblende MgSe is 0.59 nm.[1][2] The wurtzite structure of MgSe has been observed, but it is unstable and slowly converts to the rock-salt structure.[5]

NiAs- and FeSi-type crystal structures of MgSe are predicted to form by subjecting the rock-salt crystal structure to extremely high pressures.[2]

Electronic properties

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Both rock-salt and zincblende MgSe are semiconductors. On the basis of different extrapolations, a room temperature bandgap of 4.0 eV has been recommended for zincblende MgSe.[1][2] A room temperature bandgap of 3.9 eV was determined for rock-salt MgSe.[2][3]

Preparation

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Thin films of amorphous, wurtzite and rock-salt MgSe have been prepared by vacuum deposition of Mg and Se at cryogenic temperatures, followed by heating and annealing.[5] Compound semiconductor alloys of MgSe, such as MgxZn1-xSe, have been prepared by molecular beam epitaxy.[3][4]

Reactions

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Samples of pure MgSe and Mg-rich MgxZn1-xSe (x > 0.7) readily react with water and oxidize in air.[2][3]

References

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  1. ^ a b c d e Adachi, S., ed. (2004). "Zincblende Magnesium Selenide (β-MgSe)". Handbook on Physical Properties of Semiconductors. Kluwer Academic Publishers. pp. 37–50. doi:10.1007/1-4020-7821-8_3. ISBN 978-1-4020-7820-0.
  2. ^ a b c d e f g h Madelung, O., Rössler, U., Schulz, M., eds. (1999). "Magnesium oxide (MgO) physical properties (MgSe)". II-VI and I-VII Compounds; Semimagnetic Compounds. Landolt-Börnstein - Group III Condensed Matter. Vol. 41B. Springer-Verlag. pp. 1–8. doi:10.1007/10681719_218. ISBN 978-3-540-64964-9.
  3. ^ a b c d e Jobst, B., Hommel, D., Lunz, U., Gerhard, T., Landwehr, G. (1996). "E0 band-gap energy and lattice constant of ternary Zn1−xMgxSe as functions of composition". Applied Physics Letters. 69 (1): 97–99. doi:10.1063/1.118132. ISSN 1077-3118.
  4. ^ a b Okuyama, H., Nakano, K., Miyajima, T., Akimoto, K. (1992). "Epitaxial growth of ZnMgSSe on GaAs substrate by molecular beam epitaxy". Journal of Crystal Growth. 117 (1–4): 139–143. Bibcode:1992JCrGr.117..139O. doi:10.1016/0022-0248(92)90732-X. ISSN 0022-0248. S2CID 97851344.
  5. ^ a b Mittendorf, H. (1965). "Röntgenographische und optische Untersuchungen aufgedampfter Schichten aus Erdalkalichalkogeniden". Zeitschrift für Physik (in German). 183 (2): 113–129. Bibcode:1965ZPhy..183..113M. doi:10.1007/BF01380788. ISSN 1434-6001. S2CID 121137813.