Piezoelectric properties of (Na1−xKx)NbO3-based lead-free piezoelectric ceramics and their application in knocking sensor

Dae Hyeon Kim, Tae Gon Lee, Sung Hoon Cho, Ku Tak Lee, Chong Yun Kang, Won Kyoung Lee, Chung Kook Lee, Sahn Nahm

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


Piezoelectric knocking sensors with a dense microstructure were fabricated at 960°C for 2 hours using various CuO-added (Na0.5K0.5)NbO3 (NKN)-based piezoelectric ceramics. The practical sensitivity (SP) of the knocking sensor, which is the ability to detect the knocking of a car engine, was influenced by the g33 × kp value of the piezoelectric ceramics, indicating that the g33 × kp can be considered a figure of merit of the piezoelectric ceramics used in the knocking sensor. The knocking sensor synthesized using the CuO-added 0.95(Na0.5K0.5)(Nb0.95Sb0.05)O3–0.05CaTiO3 (CNKNS–CT) ceramic, which showed a g33 of 25.7 Vm/N and kp of 0.46, exhibited a high SP of 119 mV/g at the resonance frequency. The SP of the commercial knocking sensor, which was synthesized using the Pb(Zr,Ti)O3 (PZT)-based ceramic, was 112 mV/g at the resonance frequency. Hence, the knocking sensor fabricated using the CNKNS–CT piezoelectric ceramic can be used to replace the commercial PZT-based knocking sensor.

Original languageEnglish
Pages (from-to)5367-5373
Number of pages7
JournalJournal of the American Ceramic Society
Issue number12
Publication statusPublished - 2017 Dec

Bibliographical note

Funding Information:
This work was supported by the Technological Innovation R&D Program (S2329694, Development of Environment Friendly Knocking Sensor using Lead-Free Piezoelectric Ceramics) funded by the Small and Medium Business Administration (SMBA, Korea). The authors thank the KU-KIST graduate school program of Korea University.

Publisher Copyright:
© 2017 The American Ceramic Society


  • lead-free ceramics
  • piezoelectric materials/properties
  • sensors

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry


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