Effects of MnO2 doping on structure, dielectric and piezoelectric properties of 0.825NaNbO3–0.175Ba0.6(Bi0.5K0.5)0.4TiO3 lead-free ceramics

Authors

  • Ximing Fan,

    1. College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China
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  • Dunmin Lin,

    Corresponding author
    1. College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China
    • Phone: +86 28 84760802, Fax +86 28 84767868
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  • Qiaoji Zheng,

    Corresponding author
    1. College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China
    • College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China.
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  • Hailing Sun,

    1. College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China
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  • Yang Wan,

    1. College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China
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  • Xiaochun Wu,

    1. College of Chemistry and Materials Science, and Visual Computing and Virtual Reality Key Laboratory of Sichuan Province, Sichuan Normal University, Chengdu 610066, P. R. China
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  • Lang Wu

    1. State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, P. R. China
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Abstract

Lead-free ceramics 0.825NaNbO3–0.175Ba0.6(Bi0.5K0.5)0.4TiO3 + xmol% MnO2 were prepared by an ordinary sintering technique and the effects of MnO2 doping on the structure, dielectric, and piezoelectric properties of the ceramics were studied. The ceramics with perovskite structure are transformed from tetragonal to pseudocubic phases by increasing the doping level of MnO2. After the addition of MnO2, the Curie temperature TC of the ceramics decreases and the ferroelectric–paraelectric phase transition at TC becomes more diffusive. Because of the donor and acceptor doping effects of Mn ions simultaneously, the piezoelectric constant d33, electromechanical coupling coefficient kp, relative permittivity εr, and mechanical quality factor Qm are enhanced considerably after the addition of 1 mol% MnO2. The ceramic with 1 mol% MnO2 doping possesses the optimum piezoelectricity (d33 = 131 pC/N and kp = 21.8%) and relatively high Qm = 627.

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