Preparation of transparent AlON from powders synthesized by novel CRN method

•A new method was used to prepare pure nanometer AlON powder at low temperature.•During the CRN process, the phase transition and growth of Al2O3 particles was effectively retarded by the amorphous carbon nano-layers.•Pressureless sintering yielded transparent AlON ceramic with high transparency rates of 82.5 % and 83.4 % at 400 and 1100 nm.•This method provides a new direction for the synthesis of high-quality AlON nano-powders at low temperature.