Gallium(III) oxide

• Gallium oxide ( ambiguous )
• Digalliumtrioxid

White crystalline solid

Fixed

6.44 g · cm -3

1900 ° C.

Insoluble in water

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Gallium ( III) oxide is a chemical compound of gallium and one of the oxides. The colorless, crystalline solid occurs in five modifications.

Production and representation

Gallium (III ) oxide can be obtained by dehydration of gallium hydroxide at 500 ° C.

An alternative is the decomposition of gallium nitrate at 200 ° C. The two display paths lead to different modifications, which react at higher temperatures to the most stable β - modification.

Properties

Modifications of the gallium ( III) oxide is denoted by the Greek letters α to ε. The most stable is the monoclinic β - modification. If gallium drained, formed first of the γ - modification, the structure is a spinel structure with Galliumdefekten. With prolonged heating, fades into the α - Ga2O3 - modification with corundum and finally in β - Ga2O3.

In the reaction pathway via gallium nitrate is initially formed the bixbyite -type δ - modification, which also converts to β - Ga2O3 at stronger heating above the orthorhombic ε - phase.

Several Galliumoxidmodifikationen show photocatalytic activity in the decomposition of aromatic compounds such as benzene or toluene. It is higher than that of commonly used titanium (IV ) oxide.

Use

Gallium ( III) oxide is the starting material for the production of gadolinium gallium garnet for magnetic domain memories.