Synthesis of Structurally Defined Ta3N5 Particles by Flux-Assisted Nitridation

The synthesis of a transition metal nitride, Ta3N5, was studied. Morphological changes of Ta3N5 w 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 Ta3N5 were obtained using Zn, NaCl, or Na2CO3 as a flux. Flux-assisted nitridation of TaCl5 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 Ta3N5 particles with a rectangular parallelepiped shape were produced from TaCl5-NaCl or Ta2O5-Na2CO3 mixtures by nitridation above 1123 K, because of the annealing effect of the flux.