Aluminium telluride

Inorganic compound

Aluminium telluride
Names
Other names μ-Telluride(ditelluroxo)dialuminium, Dialuminium tritelluride, Aluminium (III) telluride
Identifiers
CAS Number	12043-29-7^Y
3D model (JSmol)	Interactive image
ChemSpider	22797847^Y
ECHA InfoCard	100.031.751
EC Number	234-939-4
PubChem CID	12674524
CompTox Dashboard (EPA)	DTXSID601014260
InChI InChI=1S/2Al.3Te^Y Key: RETRTUZSQWNRQG-UHFFFAOYSA-N^Y InChI=1S/2Al.3Te/q2+3;3-2 Key: IBHHFWUKPAWXSJ-UHFFFAOYSA-N
SMILES [Te]=[Al][Te][Al]=[Te]
Properties
Chemical formula	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)
Solubility in water	decomposes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

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 → Al₂Te₃

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]

Al₂Te₃ + 6 HCl → 3 H₂Te + 2 AlCl₃

References

^ ^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.