Synthesis of Structurally Defined Ta₃N₅ Particles by Flux-Assisted Nitridation

The synthesis of a transition metal nitride, Ta 3 N 5, was studied. Morphological changes of Ta 3 N 5 particles, depending on the synthetic method, starting materials, and nitridation conditions, were examined in detail. Flux-assisted nitridation was found to be a facile one-step route to a metal nitride with morphological control of the resulting particles. Scanning electron microscopy (SEM) observation revealed that morphologically defined particles of Ta 3 N 5 were obtained using Zn, NaCl, or Na 2 CO 3 as a flux. Flux-assisted nitridation of TaCl 5 with Zn or NaCl produced nearly monodisperse fine particles larger than a few tens of nanometers. The size of these particles could be controlled by variation of the nitridation temperature. Highly crystallized Ta 3 N 5 particles with a rectangular parallelepiped shape were produced from TaCl 5 −NaCl or Ta 2 O 5 −Na 2 CO 3 mixtures by nitridation above 1123 K, because of the annealing effect of the flux.