Effect of the temperature on the synthesis of (K,Na)NbO3-modified nanoparticles by a solid state reaction route

(Na_0.5K_0.5)NbO₃ (KNN)-modified nano-particulated powders, based on variations of sodium–potassium niobate, were synthesised by solid state reaction from carbonate starting materials. The nanoparticles were attained by an optimization of the raw materials particle size and particle refinement of the carbonates during their decomposition. Particle sizes between 50 and 200 nm have been obtained as a function of calcination (decomposition) temperature. The obtained powders showed a co-existence between a tetragonal phase and an orthorhombic phase. The optimization of the raw materials particle size and the particle refinement of the carbonates during their decomposition play a key role in the formation of the KNN-modified nano particles. The developed method is well suited for the production of KNN-modified nano powders at low cost for mass production.