PARTICLE GROWTH DURING CALCINATION OF POLYCATION OXIDES SYNTHESIZED BY THE POLYMERIC PRECURSORS METHOD

The particle-growth kinetics of sodium niobate and zirconium titanate powders that were processed by the polymeric precursors method were st udied, The growth kinetics that were studied for the particle, in the final stage of crystallization, showed that the growth process occurs in two different stages. For temperatures <800 degrees C, the particle -growth mechanism is associated with surface diffusion, with an activa tion energy in the range of 40-80 kJ/mol, For temperatures >800 degree s C, particle growth is controlled by densification of the nanometric particle clusters and by a neck-size-controlled particle-growth mechan ism, The results suggest that this behavior was typical of the synthes is method, because two different polycation oxides presented the same behavior.