Aluminium telluride
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| Other names
μ-Telluride(ditelluroxo)dialuminium, Dialuminium tritelluride, Aluminium (III) telluride
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.031.751 |
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| Al2Te3 | |
| Molar mass | 436.76 g/mol |
| Appearance | dark grey to black solid[1] |
| Density | 4.5 g/cm3[1] |
| Melting point | 895[2] °C (1,643 °F; 1,168 K) |
| decomposes | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Aluminium telluride is an inorganic chemical compound of aluminium and tellurium with the chemical formula Al2Te3.
Preparation
[edit]Aluminium telluride can be obtained by direct combination of aluminium metal with elemental tellurium at 1,000 °C (1,270 K; 1,830 °F).[1]
- 2 Al + 3 Te → Al2Te3
Properties
[edit]Aluminium telluride is a very air-sensitive[3] dark grey to black solid.[1] It has a band gap of 2.4 eV.[4] The compound decomposes in humid air.[5]
In its pure form, it occurs in at least two phases. The orange-red low-temperature (α) modification transforms into the yellow high-temperature (β) form at 720 °C (993 K; 1,328 °F). The conversion from β- to α-Al2Te3, which is associated with such a small enthalpy change that it cannot be observed with differential thermal analysis, takes place after prolonged annealing just below the conversion point. The α form crystallizes in the monoclinic crystal system with the lattice constants a = 13.885 Å, b = 7.189 Å, c = 4.246 Å, p = 90.21° and an additional superstructure. The β form has a monoclinic crystal structure with space group P21/c and the lattice constants a = 7.181(1) Å, b = 12.848(3) Å, c = 14.167(3) Å, and b= 90.04(2)°. This form represents a separate structure type. The tellurium atoms form a hexagonal dense packing parallel to the (001) plane; one-third of the tetrahedral vacancies are occupied by aluminium atoms, whereby the tetrahedral vacancies are occupied in such a way that a layered structure is formed. Some sources also report another form of the defect wurtzite type.[3]
Uses
[edit]Aluminium telluride is used in the semiconductor industry.[1] It can also be used to produce hydrogen telluride by reacting with hydrogen chloride.[6]
- Al2Te3 + 6 HCl → 3 H2Te + 2 AlCl3
References
[edit]- ^ a b c d e Dale L. Perry (2016). Handbook of Inorganic Compounds. CRC Press. ISBN 978-1-4398-1462-8. Retrieved 2024-07-28 – via Google Books.
- ^ N. Prabhu, J. M. Howe (1990). "The Al-Te (Aluminum-Tellurium) system". Bulletin of Alloy Phase Diagrams. 11 (2): 202–206. doi:10.1007/BF02841706.
- ^ a b Conrad, O; Schiemann, A; Krebs, B (1997). "Die Kristallstruktur von β-Al2Te3" [The Crystal Structure of β-Al2Te3]. Zeitschrift für anorganische und allgemeine Chemie (in German). 623: 1006–1010. doi:10.1002/zaac.199762301157.
- ^ Batsanov, Stepan S.; Batsanov, Andrei S. (2012). Introduction to Structural Chemistry. Springer Netherlands. p. 130. ISBN 978-94-007-4771-5. Retrieved 2024-07-17 – via Google Books.
- ^ Brauer, Georg (2 December 2012). Handbook of Preparative Inorganic Chemistry V1. Elsevier Science. p. 826. ISBN 978-0-323-16127-5. Retrieved 2024-07-17 – via Google Books.
- ^ Riedel, Erwin; Janiak, Christoph (2022). Anorganische Chemie. De Gruyter. ISBN 978-3-11-069458-1 – via Google Books.