Ceramics-Silikáty 54, (4) 320 - 324 (2010) |
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MICROSTRUCTURE, ELECTRICAL PROPERTIES AND PROCESSING DEPENDENCE OF CuO MODIFIED (Na0.52K0.48)NbO₃ CERAMICS
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Su Shi 1, Zuo Ruzhong 1, Ran Yan 1,
Zhao Wanli 1,
Wang Yiaohui 2,
Li Longtu 2
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1 Institute of Electro Ceramics & Devices, School of Materials Science and Engineering,
Hefei University of Technology, Hefei, 230009, China
2 State Key Lab of New Ceramics and Fine Processing, Department of Materials Science and Engineering,
Tsinghua University, Beijing, 100084, China
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Keywords: Lead-free piezoelectric ceramics, Dielectrics, Ferroelectrics, Piezoelectric
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The CuO modified (Na0.52K0.48)NbO₃ (NKN) piezoelectric ceramics were prepared by a solid-state reaction method. On the
one hand, CuO doping can improve the densification behavior and simultaneously promote the grain growth, however, has
little effect on the Curie temperature. On the other hand, the mechanical quality factor Qm obviously increases, the dielectric
loss tanδ decreases, and the piezoelectric constant d₃₃ and the planar electromechanical coupling coefficient kp tend to drop.
Moreover, an obvious effect comes from the sintering conditions. The 1mol% CuO doped NKN ceramics sintered at 1090 °C
for 3 h own the electrical properties: Qm = 1727, tanδ = 0.29 %, d₃₃ = 74 pC/N, kp = 0.22 and a dielectric constant εr = 410.
All these effects of CuO doping are considered to result from the liquid phase and oxygen vacancies formed during sintering. |
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