Journal of Inorganic Materials ›› 2013, Vol. 28 ›› Issue (9): 967-970.DOI: 10.3724/SP.J.1077.2013.12659

• Research Paper • Previous Articles     Next Articles

Electrical Properties of K0.5Na0.5NbO3 Lead-free Piezoceramics by Pressureless Sintering

ZHANG Dong-Sheng1, TIAN Ai-Fen2   

  1. (1. School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China; 2. School of Materials Science and Egineering, Xi'an University of Science and Technology, Xi'an 710054, China)
  • Received:2012-11-01 Revised:2012-12-28 Online:2013-09-20 Published:2013-08-14
  • Contact: TIAN Ai-Fen.
  • About author:ZHANG Dong-Sheng.
  • Supported by:

    National Natural Science Foundation of China (51075321)

Abstract: Lead-free piezoceramics K0.5Na0.5NbO3 were prepared by pressureless sintering. The effects of sintering temperature on the density and electrical properties of KNN ceramics were investigated. The results show that the density of the KNN ceramics changes dramatically in a narrow temperature range of 1065-1120℃. The density of the ceramic sintered at 1100℃ reaches 4.35 g/cm3 (95% of the theoretical density). The ceramic sintered at 1100℃ shows the best electrical properties: the maximum piezoelectric coefficient of about 118 pC/N, the maximum relative dielectric constant of 538, the minimum dielectric loss of 4.70%, the remanent polarization of 15.37 μC/cm2 and the coercive electric field of 13.16 kV/cm. The phase transformation temperature from orthorhombic to tetragonal is about 206℃, and the Curie temperature is 410℃.

Key words: potassium sodium niobate ceramics, lead-free piezoceramic, pressureless sintering

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