Gallium(I) oxide

Gallium(I) oxide, digallium monoxide or gallium suboxide is an inorganic compound with the formula Ga2O.

Production
Gallium(I) oxide can be produced by reacting gallium(III) oxide with heated gallium in vacuum:
 * $$\mathrm{Ga_2 O_3 + 4 \ Ga \longrightarrow 3 \ Ga_2 O}$$

It can also be obtained by reacting gallium with carbon dioxide in vacuum at 850 °C.
 * $$\mathrm{2 \ Ga + CO_2 \longrightarrow Ga_2O + CO}$$

Gallium(I) oxide is a by-product in the production of gallium arsenide wafers:
 * $$\mathrm{4 \ Ga + SiO_2 \longrightarrow 2 \ Ga_2O + Si}$$

Properties
Gallium(I) oxide is a brown-black diamagnetic solid which is resistant to further oxidation in dry air. It starts decomposing upon heating at temperatures above 500 °C, and the decomposition rate depends on the atmosphere (vacuum, inert gas, air).