Hydrothermal synthesis of submicron NaNbO3 powders

Nano-crystals of ferroelectric NaNbO3 phase were prepared by hydrothermal method in one step. The influence of temperature, concentration of Nb2O5 and NaOH, and reaction duration on structure and morphology was analyzed. Temperature has a marked effect on phase formation, while concentration of Nb2O5 and NaOH can affect both structure and morphology. Lower ratio of NaOH/Nb2O5 facilitates formation of orthorhombic NaNbO3. Reaction duration only plays an important role in the formation process at lower temperatures. The intermediate phases of sodium niobates may transform into NaNbO3 by prolonging reaction duration or annealing at certain temperature.