Chemistry:Magnesium selenide
| Names | |
|---|---|
| Systematic IUPAC name
Magnesium selenide | |
| Identifiers | |
3D model (JSmol)
|
|
| ChemSpider | |
| EC Number |
|
PubChem CID
|
|
| UNII | |
| |
| |
| Properties | |
| MgSe | |
| Density | 4.21 g/cm3 (rock-salt)[1] 3.32 g/cm3 (zincblende)[2] |
| Melting point | 1,290 °C; 2,350 °F; 1,560 K[2] |
| Band gap | 3.9 eV (rock-salt) (300 K) 4.0 eV (zincblende) (300 K) |
| Structure | |
| Rock-salt (cubic) Zincblende (cubic) Wurtzite (hexagonal) | |
| 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.[1] 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.[2][1] 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.[1]
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.[2][1] A room temperature bandgap of 3.9 eV was determined for rock-salt MgSe.[1][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 MgxZn1−xSe, have been prepared by molecular beam epitaxy.[3][4]
Reactions
Samples of pure MgSe and Mg-rich MgxZn1−xSe (x > 0.7) readily react with water and oxidize in air.[1][3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 "Magnesium oxide (MgO) physical properties (MgSe)". II-VI and I-VII Compounds; Semimagnetic Compounds. Landolt-Börnstein - Group III Condensed Matter. 41B. Springer-Verlag. 1999. pp. 1–8. doi:10.1007/10681719_218. ISBN 978-3-540-64964-9. http://materials.springer.com/lb/docs/sm_lbs_978-3-540-31359-5_218.
- ↑ 2.0 2.1 2.2 2.3 Cite error: Invalid
<ref>tag; no text was provided for refs namedBetaMgSe - ↑ 3.0 3.1 3.2 3.3 3.4 "E0 band-gap energy and lattice constant of ternary Zn1−xMgxSe as functions of composition". Applied Physics Letters 69 (1): 97–99. 1996. doi:10.1063/1.118132. ISSN 1077-3118.
- ↑ 4.0 4.1 "Epitaxial growth of ZnMgSSe on GaAs substrate by molecular beam epitaxy". Journal of Crystal Growth 117 (1–4): 139–143. 1992. doi:10.1016/0022-0248(92)90732-X. ISSN 0022-0248. Bibcode: 1992JCrGr.117..139O.
- ↑ 5.0 5.1 "Röntgenographische und optische Untersuchungen aufgedampfter Schichten aus Erdalkalichalkogeniden" (in German). Zeitschrift für Physik 183 (2): 113–129. 1965. doi:10.1007/BF01380788. ISSN 1434-6001. Bibcode: 1965ZPhy..183..113M.
 |  |
