The roles of Sn4+ in affecting performance of Potassium Sodium Niobate ceramics

• Published in: Journal of alloys and compounds 2022-04, Vol.899, p.163290, Article 163290
• Main Authors: Xie, Lixu, Chen, Hao, Xie, Yining, Tan, Zhi, Cheng, Yuan, Chen, Qiang, Xing, Jie, Zhu, Jianguo
• Format: Article
• Language: English
• Subjects: Ceramics; Curie temperature; Doping; Electrical properties; Grain growth; Grain size; KNN ceramics; Niobates; Perovskites; Phase transitions; Piezoelectricity; Temperature stability; Transition temperature
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.163290

•Sn4+ doping in KNN-BC-BKZ1-xSx can improve the piezoelectricity while maintaining a high Curie temperature.•The influence of doped Sn4+ content in KNN-based ceramics’ structure has been investigated through the Rietvled refinement.•The effect of Sn4+ content on temperature stability of domain structure is studied. [Display omitted] 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.