Synthesis of Aluminum Nitride Whiskers by Carbothermal Reduction

摘要

Growth mechanism and morphologies of AlN whiskers prepared by carbothermal reduction method are studied as well as the technological condition. The optimum growth condition is at 1700°C for 5 hours with flowing nitrogen (0.61/min), when the raw materials are α-Al_2O_3 and graphite (Al_2O_3: C = 4 : 1 in weight). Generally, whiskers with hexagonal cross section grow along (0001) and plate-like whiskers have a growth orientation parallel to (0111) et al. other than (0001). During the growth of whiskers, VLS mechanism and VS mechanism serve the function together. In the early stage, AlN whiskers nucleate by VLS mechanism and after the liquid catalyst disappears, VS mechanism plays the leading role.