The SEM images in Fig. 2 reveal that the addition of PCN resulted in significant changes in the microstructure of the
ceramics. Some grains are observed to have irregular shapes with both open and close pores as a result of the high rate of the evaporation of PbO during the sintering.17)The imagesalso show that the grain size of the ceramics variedconsiderably from 0.43 to 19.56mm(Table I). However,the average grain size significantly decreased with an
increase in the content of PCN. It can also be seen that the maximum density is obtained in the 0.7PZT–0.3PCN
ceramics, while the minimum density is observed in the 0.5PZT–0.5PCN ceramics. Interestingly, the density results
can be correlated to the microstructure because high-density 0.7PZT–0.3PCN ceramics show high degrees of grain close
packing, whereas low-density 0.5PZT–0.5PCN ceramics
contain many closed pores.