Gallium(III) oxide

Gallium(III) trioxide
	β-Ga2O3 crystal
	Crystal structure of β-Ga2O3
Names
	Other names gallium trioxide, gallium sesquioxide
Identifiers
CAS Number	12024-21-4 ;
3D model (JSmol)	Interactive image;
ChemSpider	139522 ;
ECHA InfoCard	100.031.525
EC Number	234-691-7;
PubChem CID	5139834;
RTECS number	LW9650000;
UNII	46F059V66A ;
CompTox Dashboard (EPA)	DTXSID9031359 ;
	InChI InChI=1S/2Ga.3O Key: QZQVBEXLDFYHSR-UHFFFAOYSA-N ; InChI=1/2Ga.3O/rGa2O3/c3-1-5-2-4 Key: QZQVBEXLDFYHSR-OGCFUIRMAC;
	SMILES O=[Ga]O[Ga]=O;
Properties
Chemical formula	Ga2O3
Molar mass	187.444 g/mol
Appearance	white crystalline powder
Melting point	1,725 °C (3,137 °F; 1,998 K)
Solubility in water	insoluble
Solubility	soluble in most acids
Structure
Crystal structure	Monoclinic, mS20, space group = C2/m, No. 12
Lattice constant	a = 1.2232 nm, b = 0.3041 nm, c = 0.5801 nm α = 90°, β = 103.73°, γ = 90° β-phase
Formula units (Z)	4
Thermochemistry
Heat capacity (C)	92.1 J/(mol·K)
Std molar; entropy (S⦵298)	85.0 J/(mol·K)
Std enthalpy of; formation (ΔfH⦵298)	−1089.1 kJ/mol
Gibbs free energy (ΔfG⦵)	−998.3 kJ/mol
Enthalpy of fusion (ΔfH⦵fus)	100 kJ/mol
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Gallium(III) oxide is an inorganic compound with the formula Ga₂ O₃. An ultra-wide-bandgap semiconductor, it has been studied for applications in power electronics, phosphors, and gas sensing. The compound has several polymorphs, of which the monoclinic β-phase is the most stable.