Electrical Properties and Relaxor Phase Evolution of Li‐Modified BNT‐BKT‐BT Lead‐Free Ceramics |
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| Authors: | Ye‐Jing Dai Zhe Zhao Xiao‐Wen Zhang Si‐Hui Wang |
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| Affiliation: | 1. Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin, China;2. The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China |
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| Abstract: | By conventional ceramics sintering technique, the lead‐free 0.85Bi0.5Na0.5(1?x)Li0.5xTiO3‐0.11Bi0.5K0.5TiO3‐0.04BaTiO3 (x =0–0.15) piezoelectric ceramics were obtained and the effects of Li dopant on the piezoelectric, dielectric, and ferroelectric properties were studied. With increasing Li addition, the temperature‐dependent permittivity exhibited the normal ferroelectric‐to‐ergodic relaxor (FE‐to‐ER) transition temperature (TFE‐ER, abbreviated as TF‐R) decreasing down to room temperature. The increasing Li content also enhanced the diffuseness of the FE‐to‐ER transition behavior. For composition with x = 0.15, a large unipolar strain of 0.37% ( = Smax/Emax = 570 pm/V) was achieved under 6.5 kV/mm applied electric field at room temperature. Both unipolar and bipolar strain curves related to the temperature closely, and when the temperature reached the TF‐R, the normalized strain  achieved a maximum value (e.g., for x = 0.10,  = 755 pm/V) owing to the electric‐field‐induced ER‐to‐FE state transition. |
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| Keywords: | strain relaxors ferroelectricity/ferroelectric materials lead‐free ceramics |
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