Gallium(III) sulfide - Misplaced Pages

(Redirected from Gallium sesquisulfide)

Gallium(III) sulfide
Names

Other names gallium sesquisulfide
Identifiers
CAS Number	12024-22-5
3D model (JSmol)	Interactive image
ECHA InfoCard	100.031.526
EC Number	234-688-0
PubChem CID	165983
CompTox Dashboard (EPA)	DTXSID70904021
InChI InChI=1S/2Ga.3S/q2+3;3-2Key: BVSHTEBQPBBCFT-UHFFFAOYSA-N
SMILES ....
Properties
Chemical formula	Ga₂S₃
Molar mass	235.644 g/mol
Appearance	yellow (α-)
Density	3.77 g/cm
Melting point	1,090 °C (1,990 °F; 1,360 K)
Solubility in water	Reacts
Magnetic susceptibility (χ)	−-80·10 cm/mol
Related compounds
Related compounds	Gallium(II) sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references

Chemical compound

Gallium(III) sulfide, Ga₂S₃, is a compound of sulfur and gallium, that is a semiconductor that has applications in electronics and photonics.

Structure

There are four polymorphs, α (hexagonal), α' (monoclinic), β(hexagonal) and γ(cubic). The alpha form is yellow. The crystal structures are related to those of ZnS with gallium in tetrahedral positions. The alpha and beta forms are isostructural with their aluminium analogues. The similarity in crystal form of gamma- with sphalerite (zinc blende), ZnS is believed to explain the enrichment of gallium in sphalerite ores.

Preparation and chemical properties

Ga₂S₃ can prepared by reacting the elements at high temperature or as a white solid by heating Ga in a stream of H₂S at high temperature (950 °C).

It may also prepared by a solid state reaction of GaCl₃ and Na₂S.

The method of production can determine the polymorphic form produced, the reaction of Ga(OH)₃ with H₂S at different temperatures is reported to produce a different polymorph depending on the temperature, α- 1020 K, β- 820 K and γ- above 873 K

Ga₂S₃ decomposes at high temperature forming the non-stoichiometric sulfide, Ga₄S_x (4.8 < x < 5.2). Ga₂S₃ dissolves in aqueous acids and decomposes slowly in moist air forming H₂S.

Ga₂S₃ dissolves in aqueous solutions of potassium sulfide, K₂S to form K₈Ga₄S₁₀ containing the (Ga₄S₁₀) anion which has an adamantane, molecular P₄O₁₀ structure.

Ternary sulfides MGaS₂, MGa₂S₄ and MGaS₃ respectively have been of interest due to their unusual electrical properties and some of these can be prepared by reactions of Ga₂S₃ with metal sulfides e.g. CdGa₂S₄:-

Ga₂S₃ + CdS → CdGa₂S₄

Although by itself Ga₂S₃ is not a glass former it can be reacted with rare earth sulfides to form glasses e.g. the reaction with lanthanum sulfide, La₂S₃, forms gallium lanthanum sulfide glass which has interesting optical properties and is a semiconductor.

References

^ Handbook of Inorganic Compounds, Dale L. Perry, Taylor & Francis, 2011, ISBN 978-1-4398-1461-1
^ The Chemistry of Aluminium, Gallium, Indium and Thallium, Anthony John Downs, 1993, ISBN 075140103X , ISBN 978-0751401035
Pardo, M.P.; Guittard, M.; Chilouet, A.; Tomas, A. (1993). "Diagramme de phases gallium-soufre et études structurales des phases solides". Journal of Solid State Chemistry. 102 (2): 423–433. Bibcode:1993JSSCh.102..423P. doi:10.1006/jssc.1993.1054. ISSN 0022-4596.
Peter Atkins; T.L. Overton; J.P. Rourke; M.T. Weller; F.A. Armstrong (2010). Inorganic Chemistry (Fifth ed.). New York: W. H. Freeman and Company. p. 346. ISBN 978-1429218207.
^ Barron, Andrew R.; MacInnes, Andrew N. (1994). "Gallium: Inorganic chemistry". In King, R. Bruce (ed.). Encyclopedia of Inorganic Chemistry. John Wiley and Sons. pp. 100–110. ISBN 0-471-93620-0.
Semiconductors: Data Handbook 3d Ed., Otfried Madelung, Springer, 2004, ISBN 978-3540404880
Semiconducting Chalcogenide Glass III: Applications of Chalcogenide Glasses, Robert Fairman, Boris Ushkov, Elsevier, 2004, (ebook), ISBN 9780080541068