Abstract
In the KNN ceramics system, the contradictory relationship between piezoelectricity and phase transition temperature has received extensive attention from researchers. Herein, by studying the doping mechanism of Sn4+ in 0.957(K0.48Na0.52)NbO3-0.003BiCoO3-0.04(Bi0.5K0.5)Zr1-xSnxO3 (KNN-BC-BKZ1-xSx), the coexistent of excellent piezoelectricity and ideal Curie temperature is realized in KNN ceramics. The addition of Sn4+ keeps R-O-T coexistence system in KNN-BC-BKZ1-xSx ceramics, thereby maintaining the low energy barrier of domain rotation. Further investigation has shown that the substitution of Sn4+ can promote grain growth and increase the density of ceramics. In addition, the optimal comprehensive properties (d33 = 391 pC/N, kp = 0.518, TC = 332 °C, d33* = 512 pm/V) are simultaneously obtained at x = 0.15. Particularly, due to growth of grain size, excellent temperature stability is obtained within a broad temperature range. The discovery of Sn4+ doping is useful to the development of KNN-based materials with both piezoelectric electrical properties and Curie temperature as it provides a new idea for enhancing performances of ceramics.
NSTL
Elsevier