{'fraction_non_alphanumeric': 0.023917995444191344, 'fraction_numerical': 0.02050113895216401, 'mean_word_length': 5.463235294117647, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Synthesis and sintering properties of aluminium nitride nanopowder prepared by the gas-reduction–nitridation method

Aluminium nitride (AlN) nanopowder was successfully synthesized from transition alumina nanopowder via a new single-step nitridation process. A gas mixture of NH3–C3 H8 was employed as a reduction–nitridation agent, which enables direct nitridation of transition alumina at processing temperatures of 1200–1400 °C. AlN powder prepared under typical reaction conditions was found to be phase-pure and nanocrystalline, with a specific surface area of 36.4 m2 g−1 and a mean particle size around 50 nm. The AlN nanopowders produced could be densified to a pore-free state in conventional processing, without resort to the use of sintering aids. SEM observation revealed markedly small grain sizes in the sintered specimens compared with the commonly processed AlN.