Enhanced piezoelectric properties and strain response in 〈001〉 textured BNT-BKT-BT ceramics

- High piezoelectric constant and electro-strain response could be obtained in textured Na0.5Bi0.5TiO3 ceramics.
- Defect dipole would stabilize ferroelectric domains and polar nanoregions under applied electric field.
- The electric-field-induced transition could appear at lower electric field for textured Na0.5Bi0.5TiO3 ceramics.

Highly 〈001〉 textured (~ 81%) ternary BNT-BKT-BT ceramics are prepared by reactive templated grain growth (RTGG) method with plate-like Bi4Ti3O12 particles as templates. Outstanding electric properties, which are both higher than state of art BNT-based ceramics, emerge in the aforementioned sample due to the grain orientation. For the textured ceramics, a high piezoelectric constant d33 of 314 pC/N could be obtained, which is ~ 1.4-fold larger than that of a random one (221 pC/N). A high electro-strain response (~ 0.41%) is obtained at a low applied electric field (4 kV/mm) in textured ceramics, with the normalized strain d33⁎ (Smax/Emax) = 1030 pm/V near the TF-R (the temperature of ferroelectric to ergodic relaxor state transition). Moreover, the evolution process of relaxor phases is studied. The texture technique also could improve the TF-R from 70 °C to 100 °C, enhancing the temperature stability. In addition, the polarization switching process in ferroelectric phase and ergodic relaxor state are analyzed in this work, respectively.

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