Effect of carbon monoxide on the carbothermal reduction and nitridation reaction of alumina

Abstract

The carbothermal reduction and nitridation (CRN) of alumina (Al 2O 3) to aluminum nitride (AlN) were investigated under a flow of mixed gas of nitrogen and carbon monoxide (CO). The powders obtained by calcining the (hydroxo)(succinato)Al(III) complex under a flow of the mixed gas with different CO contents were characterized by powder XRD and 27Al magic-angle spinning (MAS) NMR spectroscopy. The complex decomposed into ρ-Al 2O 3, which was then converted into either AlN or δ-Al 2O 3 through γ-Al 2O 3, depending on the CO content in the mixed gas. The CRN reaction of Al 2O 3 became more retarded with increasing content of CO in the mixed gas.