Effect of potassium content on the dielectric and electrical properties of sodium potassium niobate ceramics

(K x Na 1−x ) NbO3 ceramics or KNN is considered as one of the most promising candidates for lead-free piezoelectric applications, because of its high Curie temperature and good electrical properties. However, it is well known that dense and well-sintered KNN ceramics are very difficult to obtain by conventional sintering process because of the high volatility of alkali elements at high temperatures. The major strategy to overcome this problem is simply adding excess alkali metals in the starting composition.