Magnesium selenide

Magnesium selenide
Names
	Systematic IUPAC name Magnesium selenide
Identifiers
CAS Number	1313-04-8;
3D model (JSmol)	Interactive image;
ChemSpider	66597;
ECHA InfoCard	100.013.820
EC Number	215-201-0;
PubChem CID	73969;
UNII	N7813M82QS;
CompTox Dashboard (EPA)	DTXSID1061659 ;
	InChI InChI=1S/Mg.Se/q+2;-2 Key: AZUPEYZKABXNLR-UHFFFAOYSA-N;
	SMILES [Mg+2].[Se-2];
Properties
Chemical formula	MgSe
Molar mass	103.27 g/mol
Density	4.21 g/cm3 (rock-salt); 3.32 g/cm3 (zincblende)
Melting point	1,290 °C; 2,350 °F; 1,560 K
Band gap	3.9 eV (rock-salt) (300 K); 4.0 eV (zincblende) (300 K)
Structure
Crystal structure	Rock-salt (cubic); Zincblende (cubic); Wurtzite (hexagonal)
Lattice constant	a = 0.55 nm (rock-salt); a = 0.59 nm (zincblende); a = 0.415 nm, c = 0.672 nm (wurtzite)
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). Infobox references

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.

Structure

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 Mg_xZn_1-xS_ySe_1-x and Mg_xZn_1-xSe grown on gallium arsenide, the latter of which was prepared with a high magnesium content (up to 95% Mg, i.e., Mg_0.95Zn_0.05Se).^[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

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

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 Mg_xZn_1-xSe, have been prepared by molecular beam epitaxy.^[3]^[4]

Reactions

Samples of pure MgSe and Mg-rich Mg_xZn_1-xSe (x > 0.7) readily react with water and oxidize in air.^[2]^[3]

References

^ ^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.
^ ^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.
^ ^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 Zn_1−xMg_xSe as functions of composition". Applied Physics Letters. 69 (1): 97–99. doi:10.1063/1.118132. ISSN 1077-3118.
^ ^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.
^ ^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.

[BetaMgSe-1] 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.

[Madelung1999a-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.

[Jobst1996a-3] Jobst, B., Hommel, D., Lunz, U., Gerhard, T., Landwehr, G. (1996). "E₀ band-gap energy and lattice constant of ternary Zn_1−xMg_xSe as functions of composition". Applied Physics Letters. 69 (1): 97–99. doi:10.1063/1.118132. ISSN 1077-3118.

[Okuyama1992a-4] 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.

[Mittendorf1965a-5] 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.

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