Electromechanical and ferroelectric properties of (Bi1/2Na 1/2)TiO3-(Bi1/2K1/2)TiO 3- (Bi1/2Li1/2)TiO3-BaTiO 3 lead-free piezoelectric ceramics for accelerometer application

S. H. Choy, X. X. Wang, H. L.W. Chan, C. L. Choy

Research output: Journal article publicationJournal articleAcademic researchpeer-review

38 Citations (Scopus)

Abstract

Lead-free (0.90-x)(Bi1/2Na1/2)TiO3-0. 05(Bi1/2K1/2)TiO3-x(Bi1/2Li 1/2)TiO3-0.05BaTiO3 piezoelectric ceramics (abbreviated as BNKLBT-100x, with x ranged from 0 to 2.5 mol∈%) were prepared by a conventional mixed oxide method. Effects of the amount of (Bi 1/2Li1/2)TiO3 (BLT) on the electrical properties and crystal structure of the BNKLBT ceramics were examined. BNKLBT-1.5 ceramics have good properties with piezoelectric constant d 33=163 pC/N, electromechanical coupling factor kp=0.33, kt=0.53, relative permittivity εr=785 and dissipation factor cosδ=2.2% at 1 kHz. The sample has larger remnant polarization than BNKLBT-0 ceramics and the same coercive field as BNKLBT-0 ceramics. X-ray diffraction analysis shows that the incorporated BLT diffuses into the BNT-BKT-BT lattice to form a solid solution during sintering, but changes the crystal structure from rhombohedral to tetragonal symmetry at higher BLT amounts. Depolarization temperature (Td) of the BNKLBT-100x ceramics increases from 102 °C to ∼ 136 °C for BNKLBT-0 to BNKLBT-2.5. BNKLBT-1.5 is used as the transduction element in compressive type accelerometer and its sensitivity is calibrated by the back-to back method. Within the ±2.5% tolerance, the lead-free accelerometer has a mean value of 2.97 pC/ms-2 within 50 Hz-12.45 kHz and the lead-based accelerometer has a mean value of 4.34 pC/ms-2 within 50 Hz to 8.24 kHz.

Original languageEnglish
Pages (from-to)775-781
Number of pages7
JournalApplied Physics A: Materials Science and Processing
Volume89
Issue number3
DOIs
Publication statusPublished - 1 Nov 2007

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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