Dielectric and sintering properties of NaNbO_3 ceramic prepared by Pechini method

摘要

NaNbO_3 powders and ceramics were prepared by Pechini method. The pure phase NaNbO_3 was obtained at temperature as low as 350℃, and then they obtained fine powders were used to prepared ceramics through conventional sintering process. The effect of sintering temperature on microstructure evolution and dielectric properties of NaNbO_3 ceramics has been determined. Results shown that the microstructure of NaNbO_3 ceramics consisted of stacked plates, which was related the liquid phase. It was important to note that the stacked plate configuration forming the grain has not been emphasized before, and these grains support adequate wetting characteristics for the liquid phase in order to achieve fully dense microstructure. Above 1195℃, a number of angular grains with flat interfaces started to appear, and joined to each other with the sintering temperature increase. The effect of grains morphology on dielectric properties of the NaNbO_3 ceramics was also detected.