AlN Synthesis via 5.8 GHz Microwave Carbothermal Reduction-nitridation of Alumina

Abstract

Aluminum nitride (AlN) was synthesized by carbothermal reduction and nitridation from a mixture of Al₂O₃ and carbon black by 5.8 GHz microwave E-field irradiation using single-mode cavity. The apparent activation energy was analyzed by Arrhenius plot of the nitridation ratio of the synthesized samples. The value was smaller than that in previous research using 2.45 GHz microwave irradiation. Samples synthesized by microwaves at 1000-1100 °C were able to maintain the spherical shape of pristine alumina, but the samples at °C or higher were sintered.