Chemistry:Aluminium telluride

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Short description: Inorganic compound
Aluminium telluride
Names
Other names
μ-Telluride(ditelluroxo)dialuminium, Dialuminium tritelluride, Aluminium (III) telluride
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 234-939-4
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).
Infobox references

Aluminium telluride is an inorganic chemical compound of aluminium and tellurium with the chemical formula Al2Te3.

Preparation

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 → Al
2
Te
3

Properties

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

Aluminium telluride is used in the semiconductor industry.[1] It can also be used to produce hydrogen telluride by reacting with hydrogen chloride.[6]

Al
2
Te
3
+ 6 HCl → 3 H
2
Te + 2 AlCl
3

References

  1. 1.0 1.1 1.2 1.3 1.4 Dale L. Perry (2016). Handbook of Inorganic Compounds. CRC Press. ISBN 978-1-4398-1462-8. https://books.google.com/books?id=SFD30BvPBhoC&pg=PA488. Retrieved 2024-07-28. 
  2. 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. 
  3. 3.0 3.1 Conrad, O; Schiemann, A; Krebs, B (1997). "Die Kristallstruktur von β-Al2Te3". Zeitschrift für anorganische und allgemeine Chemie 623: 1006–1010. doi:10.1002/zaac.199762301157. https://onlinelibrary.wiley.com/doi/epdf/10.1002/zaac.199762301157. 
  4. Batsanov, Stepan S.; Batsanov, Andrei S. (2012). Introduction to Structural Chemistry. Springer Netherlands. p. 130. ISBN 978-94-007-4771-5. https://books.google.com/books?id=YiHHkIA7K4MC&pg=PA130. Retrieved 2024-07-17. 
  5. Brauer, Georg (2 December 2012). Handbook of Preparative Inorganic Chemistry V1. Elsevier Science. p. 826. ISBN 978-0-323-16127-5. https://books.google.com/books?id=kaa2qeFRXmUC&pg=PA826. Retrieved 2024-07-17. 
  6. Riedel, Erwin; Janiak, Christoph (2022). Anorganische Chemie. De Gruyter. ISBN 978-3-11-069458-1. https://books.google.com/books?id=aXdWEAAAQBAJ.