Preparation of nanometer AlN powders by combining spray pyrolysis with carbothermal reduction and nitridation

Nanometer AlN powders were prepared by combining spray pyrolysis with carbothermal reduction and nitridation (CRN). The aluminum oxide/carbon composite powders prepared by spray pyrolysis from a sucrose spray solution were several microns in size, with hollow and porous structures. Precursor powder with 67 wt% carbon content was transformed into phase-pure AlN powder by CRN at temperatures above 1,400 °C. The hollow-structured AlN powder was ground to 20 nm mean size by simple milling.