Lead-free piezoelectric ceramics with compositions around the morphotropic phase boundary (MPB) x(Na0.5Bi0.5)TiO3-y(K 0.5Bi0.5)TiO3-zBaTiO3 [x + y + z = 1; y : z = 2:1] were synthesized using conventional, solid-state processing. Dielectric maximum temperatures of 280° C and 262° C were found for tetragonal 0.79(Na0.5Bi0.5)TiO3-0.14(K 0.5Bi0.5)TiO3-0.07BaTiO3 (BNBKT9) and MPB composition 0.88(Na0.5Bi0.5)TiO 3-0.08(K0.5Bi0.5)TiO3-0.04BaTiO 3 (BNBK88), with depolarization temperatures of 224°C and 162°C, respectively. Piezoelectric coefficients d33 were found to be 135 pC/N and 170 pC/N for BNBK79 and BNBK88, and the piezoelectric d 31 was determined to be -37 pC/N and - 51 pC/N, demonstrating strong anisotropy. Coercive field values were found to be 37 kV/cm and 29 kV/cm for BNBK79 and BNBK88, respectively. The remanent polarization of BNBK88 (∼40 μC/cm2) was larger than that of BNBK79 (∼29 μC/cm 2). The piezoelectric, electromechanical, and high-Held strain behaviors also were studied as a function of temperature and discussed.
|Original language||English (US)|
|Number of pages||7|
|Journal||IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control|
|State||Published - May 2007|
All Science Journal Classification (ASJC) codes
- Acoustics and Ultrasonics
- Electrical and Electronic Engineering