One method of preparing GaBr3 is to heat elemental gallium in the presence of liquid bromine under vacuum. After the highly exothermic reaction, the mixture is allowed to stand and then subjected to various purification steps. This method has remained a useful method for preparing GaBr3 since the early 1900s. Historically, gallium was obtained by electrolysis of hydroxide in a KOH solution, but today it is obtained as a by-product of aluminum and zinc production.
GaBr3 can also be produced by the chemical combination of Ga(s) and Br(g) in an anhydrous, oxygen-free, organic and grease-free environment. The reaction products are gases that must be crystallized to form the laboratory purchased GaBr3 solid:
Ga(s) + 3Br(l) → GaBr3(g)
