Air & Water Reactions
Insoluble in water.
white odourless powder
Odorless fine white powder. Insoluble in water.
White crystals; exists in three crystalline modifications: alpha-, beta-, and gamma-Ga2O3; while the alpha-form is analogous to the corundum form of alumina, the beta-Ga2O3 is isomorphous with theta-alumina; alpha-form converts to beta-modification on calcination at high temperatures (600°C); gamma form is stable at low temperatures; density 6.44 g/cm3 (alpha-Ga2O3), 5.88 g/cm3 (beta- Ga2O3); melts at 1,725°C; soluble in most acids.
In semiconductors; gas sensing; catalysis. Nanostructures as blue and UV light emitters in optoelectronic device applications.
SYMPTOMS: Symptoms of exposure to GALLIUM(III) OXIDE include reduction of red blood cells and platelets, anemia, skin rash and nausea.
Gallium sesquioxide is reduced to gallium suboxide, Ga2O [12024-20-3] by common reducing agents. Also, heating the sesquioxide with gallium metal yields gallium suboxide. Heating with magnesium reduces the oxide to elemental form in a violent reaction:
Ga2O3 + 3Mg →2Ga + 3MgO
Heating with mineral acids yields corresponding gallium salts. When heated with a mixture of hydrogen and arsenic vapors at 600°C, gallium arsenide, GaAs is produced. When heated with alkali metal oxide at 1,000°C, alkali metal gallates, such as K2Ga2O6 are formed.
The compound is used in spectroscopic analysis and in preparing gallium arsenide for making semiconductors.
Flash point data for GALLIUM(III) OXIDE are not available; however, GALLIUM(III) OXIDE is probably combustible.
GALLIUM(III) OXIDE may react with acids. Heating (to 1292° F) with magnesium causes a violent reduction to metallic slate.
Gallium sesquioxide is precipitated in hydrated form upon neutralization of acidic or basic solution of gallium salt. Also, it is prepared by thermal decomposition of gallium salts. Gallium oxide hydroxide, GaOOH [20665-52- 5] on calcinations at high temperatures yields beta- Ga2O3.