The optimal sintering atmosphere and defect structure of CuO-doped NKN-based ceramic with p/n-type conduction mechanism

• Published in: Journal of materials science. Materials in electronics 2021, Vol.32 (2), p.1928-1940
• Main Authors: Wang, Zhenxing, Huan, Yu, Wang, Huizhong, Qiu, Yu, Feng, Yue, Wei, Tao, Yang, Changhong
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Current carriers; Dielectric properties; Doping; Hall effect; Materials Science; Optical and Electronic Materials; Piezoelectricity; Sintering
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-04961-9

The chemical doping and sintering atmosphere have great influence on the defect structure and piezoelectric properties of (Na,K)NbO 3 (NKN)-based ceramics. In this work, p/n-type NKN-based ceramics are designed by introducing different CuO doping contents. The defect configuration is analyzed by Rietveld refinement, Hall-effect measurement and impedance spectroscopy. The undoped and 3 mol% CuO-doped ceramics exhibit an n-type conduction mechanism. When n-type ceramics are sintered in air, the electron concentration will decrease, resulting in the better piezoelectric and dielectric properties than that sintered in N 2 . Nevertheless, 1 mol% CuO-doped ceramics exhibit a p-type conduction mechanism. The generation of holes can be suppressed when p-type ceramics are sintered in N 2 , which is beneficial to improve their piezoelectric and dielectric properties. The experimental results suggest that the p/n-type behavior can be judged by defect analysis and the optimal sintering atmosphere of NKN-based ceramics can be predicted by analyzing the charge carrier behavior of p/n-type ceramics.