Synthesis and formation mechanism of cubic ZrN nanopowders by mechanochemical reaction of ZrCl4 and Li3N

Abstract A mixture of tetrachloride (ZrCl 4 ) and lithium nitride (Li 3 N) powders was milled in a high-energy ball mill under Ar ambient. Mechanochemical reaction of ZrCl 4 and Li 3 N occurred during the milling process and produced LiCl and ZrN with rocksalt structure. It was found by in situ measurement of surface temperature of the vial in milling process that the reaction began as milling time reached about 7 min and finished in a few of seconds, accompanied by release of a great deal of heat. This result implies that the reaction is a self-propagating one, and that ZrN powders can be fabricated by milling in very short time. By chemical separation of the products, high pure ZrN powders with nanometer scale were obtained. The present work provides a technique for synthesis of high pure ZrN nanopowders with short time, large mass and low cost. The thermodynamic and kinetic mechanisms of formation of the ZrN are discussed in detail.