Effect of high density and reduced ionic defects on piezoelectric behavior of KNaNbO ceramic.

A reduced concentration of ionic defects along with >99 % of the theoretical density has been achieved for KNaNbO ceramic by employing a twofold sintering technique. Lower concentration of ionic defects resulted in an order of magnitude improvement in the resistivity and hence enhanced poling of the ceramic at 100 °C. High density and improved poling of the ceramic resulted in a significant improvement in electromechanical properties while maintaining the high orthorhombic-tetragonal ( T) and Curie ( T) temperatures of KNaNbO (200 and 395 °C respectively). A comparison with the previous studies suggested that the piezoelectric properties of the ceramic synthesized in this study were similar to those synthesized using complex techniques such as spark plasma sintering and hot pressing. This is a significant advancement facilitating the possibility of transition of KNaNbO ceramic toward device application. [ABSTRACT FROM AUTHOR]