Defect suppression in CaZrO3‐modified (K,Na)NbO3‐based lead‐free piezoceramic by sintering atmosphere control |
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| Authors: | Hao‐Cheng Thong Qi Li Mao‐Hua Zhang Chunlin Zhao Kevin Xiu Huang Jing‐Feng Li Ke Wang |
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| Affiliation: | 1. State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China;2. School of Materials Science and Engineering, University of New South Wales, Sydney, NSW, Australia;3. Center for Flexible Electronics Technology, Tsinghua University, Beijing, China |
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| Abstract: | During high‐temperature crystal growth, lattice defects will inevitably form inside piezoelectric materials, which can be a hindrance for performance optimization. Through appropriate atmosphere control during sintering, defect levels inside the piezoelectric material can be regulated. Herein, CaZrO3‐modified (K, Na)NbO3‐based lead‐free piezoelectric ceramics with a nominal composition of 0.95(Na0.49K0.49Li0.02)(Nb0.8Ta0.2)O3‐0.05CaZrO3 are produced by sintering in an oxygen‐rich atmosphere. Compared with an air‐sintered sample, the piezoelectric constant of the oxygen‐sintered sample has greatly improved 15% up to 390 pC/N, which is comparable to commercial lead‐based counterparts. In addition, the planar electromechanical coupling factor kp is enhanced from 0.46 to 0.52. A qualitative model related to defect engineering is proposed to support the experimental observations. Our results indicate the feasibility of purposely optimizing the piezoelectric performance by sintering atmosphere control. |
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| Keywords: | defects ferroelectricity/ferroelectric materials lead‐free ceramics piezoelectric materials/properties sinter/sintering |
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