Enhanced electromechanical response in (K, Na)NbO3-based ferroelectrics by phase boundary and nonstoichiometry engineering. (1st March 2023)

• Record Type: Journal Article
• Authors: Liu, Weipeng; Zhou, Benwei; Wang, Hualong; Li, Chengjun; Du, Yi; Cheng, Chuanbing
• Is Part Of: Materials science in semiconductor processing. Volume 155(2023)
• Publication Date: 2023-03-01
• Subjects: Lead-free ceramics -- (K -- Na)NbO3 based -- Nonstoichiometry -- Phase boundary; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2022.107239
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Compositional fluctuation of the K and Na elements during the preparation process becomes a major issue for (K, Na)NbO3 (KNN) lead-free ceramics to maintain relatively stable electrical properties. The raw material Bi2 O3 is more sensitive to high temperature. To improve electrical properties, it is more necessary to compensate the volatile Bi. In this work, the 0.96K0.48 Na0.52 Nb0.96 Sb0.04 O3 -0.04Bi0.5*(1+ x ) Na0.5 ZrO3 ( x = −0.05, −0.02, 0.00, 0.02, 0.05, and 0.08) ceramics were selected as basis material. The excess Bi can increase the phase fraction of the T phase and decrease oxygen vacancy content, which effectively enhance the extrinsic contribution of the piezoelectric response. The electromechanical properties were optimized by excess Bi, and the optimal properties ( d 33 = 522 pC/N, k p = 58.9%, T c = 235 °C) were obtained in the ceramic with x = 0.05. The present work provides new guidelines for enhancing the piezoelectric performance of KNN ceramics by a simple method, which can be applied to other lead-free piezoelectric ceramic systems.