Effect of SrTiO3 template on electric properties of textured BNT–BKT ceramics prepared by templated grain growth process

• Plate-like SrTiO3 particles with uniform microstructure were prepared.
• The 〈0 0 l〉 textured BNT–BKT–ST ceramics were fabricated with high degree of orientation (f > 90%).
• The relationship between the phase structure and the electrical properties was investigated.
• Encouraging results of large strain of 0.38% with normalized strain Smax/Emax = 626 pm/V were obtained at critical composition.
• The textured ceramics exhibited large electrostrictive coefficient Q11 of 0.023 m4 C−2 and superior temperature stability.

In this work, 〈0 0 l〉 textured lead-free piezoelectric (1−x)(0.83 Bi0.5Na0.5TiO3–0.17Bi0.5K0.5TiO3)–xSrTiO3 (BNT–BKT–xST) ceramics were fabricated by template grain growth in combination with tape casting using plate-like SrTiO3 as a template. The effect of ST template on the grain orientation, strain behavior, dielectric, ferroelectric, pyroelectric and piezoelectric properties was systematically investigated in order to search the lead-free piezoelectric materials with an excellent actuating performance. The templated growth of 〈0 0 l〉 oriented grains on the ST template resulted in textured ceramics with brick wall microstructures and significantly high 〈0 0 l〉 texture degree corresponding to >90% Lotgering factor at 9–15 mol% ST template. Textured ceramics showed excellent strain properties as compared to the random counterparts and encouraging results of large strain of 0.38% with normalized strain Smax/Emax = 626 pm/V for the textured critical composition with 15 mol% ST template were obtained at room temperature. Furthermore, the textured ceramics with 27 mol% ST template exhibited large electrostrictive coefficient Q11 of 0.023 m4 C−2 and superior temperature stability compared to the random counterparts, which are very promising and makes them tremendous potential for the environmental-friendly solid-state actuator applications.