GALLIUM NITRIDE SYNTHESIS USING LITHIUM METAL AS A NITROGEN FIXANT

Micron-sized particles of gallium nitride were synthesized at temperat ures as low as 300 degrees C under ammonia in anhydrous conditions. Tw o different syntheses were investigated: compound 1 was synthesized us ing a physical mixture of gallium and lithium under flowing ammonia; c ompound 2 was synthesized using a gallium/lithium alloy under flowing ammonia. These two methods relied on the presence of lithium metal act ing as a nitrogen-fixing and transport agent for metallic gallium. Pow der X-ray diffraction demonstrated the purity and crystalline nature o f the resulting white gallium nitride; it was found to exhibit extraor dinary crystallinity considering its formation conditions. Elemental a nalysis also determined the purity of 1 and 2 and showed an absence of the lithium impurity in the former, as contrasted with 0.23% Li in th e latter. SEM demonstrated the particle sizes of 1 and 2 to be on the micron scale.