Effects of flux treatment on morphology of single-crystalline BaNbO2N particles

Abstract

The effect of different kinds of alkali halide flux treatments on the morphology of BaNbO₂N particles was investigated. BaNbO₂N powder was first synthesized by heating a mixture of BaCO₃ and Nb₂O₅ under NH₃ flow. Following synthesis, the powder was again heated under NH₃ flow but in the presence of a flux. In the case of a NaCl flux, highly crystalline cubic particles were obtained. On the other hand, a KCl flux led to the formation of truncated octahedral particles. Although particles with clear crystal habits were obtained, it was found that they were actually an aggregation of primary particles, all with the same crystal orientation. A systematic survey of the effect of the different fluxes revealed that the type of cation in the flux played a major role in determining the morphology of the BaNbO₂N particles. It was also revealed that a vaporized flux was also effective in changing the particle morphology.