Phase Transition and High Piezoelectric Properties of Li0.058(Na0.52+xK0.48)0.942NbO3 Lead-Free Ceramics

Authors

  • Hai-Tao Li,

    1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
    2. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China
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  • Bo-Ping Zhang,

    Corresponding author
    1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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  • Peng-Peng Shang,

    1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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  • Ye Fan,

    1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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  • Qian Zhang

    1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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  • S. Zhang—contributing editor

  • This work was supported by the Program for the National Natural Science Foundation of China (Grant Nos 50842028 and 50972012) and the Program of University-Industry Cooperation supported by the Ministry of Education and Guangdong Province (No. 2008B090500262), as well as by Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20090006110010).

†Author to whom correspondence should be addressed. e-mail: bpzhang@ustb.edu.cn

Abstract

Highly dense (Li,Na,K)NbO3 ceramics were prepared by normal sintering at reduced temperatures by adding excessive Na, and its phase structure and electrical properties were investigated as a function of the compensated Na content. A high piezoelectric coefficient d33 up to 279 pC/N was obtained at an optimized Na content, which was found to correspond to a phase boundary between two kinds of orthorhombic phases. The corresponding Curie temperature and electromechanical coupling factor reached 465°C and 46%, respectively. The phase boundary found in the present (Li,Na,K)NbO3 ceramics like the morphotropic phase boundary existing in the Pb(Zr,Ti)O3 system, but different from the polymorphic phase transition from an orthorhombic phase to a tetragonal one reported previously in most (Li,Na,K)NbO3 ceramics.

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