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Growth and characterization of large size lead-free ferroelectric K(Ta,Nb)O3 single crystal |
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| Authors: | Yuanyuan Zhang Shuhuan Li Fengying Liu Lihai Wang Xuping Wang Limei Zheng Liekun Yang Yuguo Yang Xianshun Lv Huajian Yu Bing Liu Jing Li Minglei Zhao Jing-Feng Li |
| Affiliation: | 1. Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
Qilu University of Technology (Shandong Academy of Sciences), Advanced Materials Institute, Key Laboratory of Light Conversion Materials and Technology of Shandong Academy of Sciences, Jinan, China;2. Department of Food Science and Engineering, Shandong Agricultural and Engineering University, Jinan, China;3. School of Physics, Shandong University, Jinan, China;4. Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China;5. Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China Qilu University of Technology (Shandong Academy of Sciences), Advanced Materials Institute, Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials, Jinan, China;6. State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, P. R. China |
| Abstract: | Lead-free piezoelectric materials with excellent performance are greatly demanded for the environmental issues. The lead-free ferroelectric single crystals are therefore greatly concerned for their much higher piezoelectricity than the polycrystalline counterparts and the domain-tunable property. However, the growth of large size and high-quality lead-free ferroelectric crystals has always been a great challenge. In this work, a ferroelectric KTa1-xNbxO3 (KTN) single crystal with an extremely large size of 25 × 25 × 37 mm3 was grown using the modified top-seeded solution growth method. The large size enabled us to carry out comprehensive investigations on the crystal. The complete sets of dielectric, piezoelectric, and elastic constants for the 001]C-poled KTN crystal with quasi single domain state were determined. Results showed that the crystal exhibits high electromechanical coupling coefficients with kt~0.642 and k33~0.679. Furthermore, the orientation dependence of the piezoelectric, dielectric, and elastic properties was determined by the tensor matrix transformation technique, and the maximum d33,  , and k33 were found along the polar direction 001]C. This work not only provides important guidance for the growth technology of lead-free ferroelectric crystals but also offers essential datasets of lead-free alkali niobate system, which is of great importance for both theoretical studies and designs of electromechanical devices. |
| Keywords: | ferroelectric KTa1-xNbxO3 single crystal full tensor properties lead-free piezoelectric materials |