抄録
Potassium niobate, K(1+x)NbO3 (KN-10000x, 10000x = 0-40), ceramics were fabricated using KHCO3 powder as a starting material to improve their density, microstructure homogeneity and piezoelectric properties. The KN-7.2 ceramic has the highest density ratio of approximately 97% among the KN-10000x ceramics, showing excess K ions are very effective for the densification. The KN-7.2 ceramics also has homogeneous microstructure with small grains with a size of about 1-3 μm. On the other hand, grains of stoichiometric KN-0 are larger than those of the KN-7.2 ceramic. Also, each grain of the KN-0 ceramic has a faceted structure. Therefore, there are many pores between the grains. Our results show the strong effect of excess K on grain growth.
