_sulfide.png) | |
| Names | |
|---|---|
| Other names gallium sesquisulfide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.031.526 |
| EC Number |
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| Properties | |
| Ga2S3 | |
| Molar mass | 235.644 g/mol |
| Appearance | yellow (α-) |
| Density | 3.77 g/cm3[1] |
| Melting point | 1,090 °C (1,990 °F; 1,360 K)[1] |
| Reacts[2] | |
| −80·10−6 cm3/mol | |
| Related compounds | |
Related compounds | Gallium(II) sulfide |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Gallium(III) sulfide, Ga2S3, is a compound ofsulfur andgallium, that is a semiconductor that has applications inelectronics andphotonics.
There are fourpolymorphs, α (hexagonal), α' (monoclinic), β(hexagonal) and γ(cubic). The alpha form is yellow. The crystal structures are related to those ofZnS with gallium in tetrahedral positions.[3][2][4] The alpha and beta forms are isostructural with their aluminium analogues.[5] The similarity in crystal form of gamma- withsphalerite (zinc blende),ZnS is believed to explain the enrichment of gallium insphalerite ores.[5]
Ga2S3 can prepared by reacting the elements at high temperature or as a white solid by heating Ga in a stream ofH2S at high temperature (950 °C).[2]
It may also prepared by a solid state reaction ofGaCl3 andNa2S.[5]
The method of production can determine the polymorphic form produced, the reaction ofGa(OH)3 withH2S 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[6]
Ga2S3 decomposes at high temperature forming thenon-stoichiometric sulfide, Ga4Sx (4.8 < x < 5.2).[5]Ga2S3 dissolves in aqueous acids and decomposes slowly in moist air formingH2S.[2]
Ga2S3 dissolves in aqueous solutions ofpotassium sulfide, K2S to form K8Ga4S10 containing the (Ga4S10)8− anion which has anadamantane,molecular P4O10 structure.[5]
Ternary sulfides MIGaS2, MIIGa2S4 and MIIIGaS3 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:-[5]
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, formsgallium lanthanum sulfide glass which has interesting optical properties and is a semiconductor.[7]