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Aluminium telluride

Names
Other names μ-Telluride(ditelluroxo)dialuminium, Dialuminium tritelluride, Aluminium (III) telluride
Identifiers
CAS Number	12043-29-7
3D model (JSmol)	Interactive image
ChemSpider	22797847
ECHA InfoCard	100.031.751
EC Number	234-939-4
PubChem CID	12674524
CompTox Dashboard (EPA)	DTXSID601014260
InChI InChI=1S/2Al.3TeKey: RETRTUZSQWNRQG-UHFFFAOYSA-N InChI=1S/2Al.3Te/q2*+3;3*-2Key: IBHHFWUKPAWXSJ-UHFFFAOYSA-N
SMILES ==
Properties
Chemical formula	Al2Te3
Molar mass	436.76 g/mol
Appearance	dark grey to black solid
Density	4.5 g/cm
Melting point	895 °C (1,643 °F; 1,168 K)
Solubility in water	decomposes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 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).

2 Al + 3 Te → Al₂Te₃

Properties

Aluminium telluride is a very air-sensitive dark grey to black solid. It has a band gap of 2.4 eV. The compound decomposes in humid air.

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.

Uses

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

Al₂Te₃ + 6 HCl → 3 H₂Te + 2 AlCl₃

References

1. ^ Dale L. Perry (2016). Handbook of Inorganic Compounds. CRC Press. ISBN 978-1-4398-1462-8. Retrieved 2024-07-28 – via Google Books.
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. ^ 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.
4. 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.
5. 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.
6. Riedel, Erwin; Janiak, Christoph (2022). Anorganische Chemie. De Gruyter. ISBN 978-3-11-069458-1 – via Google Books.

• Aluminium compounds
• Tellurides