We report a large d<sub class="emphinferior">31</sub> piezoelectric coefficient and corresponding electromechanical coupling factor, K<sub class="emphinferior">p</sub>, of 0.5Ba(Zr<sub class="emphinferior">0.2</sub>Ti<sub class="emphinferior">0.8</sub>)O<sub class="emphinferior">3</sub>-0.5(Ba<sub class="emphinferior">0.7</sub>Ca<sub class="emphinferior">0.3</sub>)TiO<sub class="emphinferior">3</sub> (BCTZ50) and 0.68Ba(Zr<sub class="emphinferior">0.2</sub>Ti<sub class="emphinferior">0.8</sub>)O<sub class="emphinferior">3</sub>-0.32(Ba<sub class="emphinferior">0.7</sub>Ca<sub class="emphinferior">0.3</sub>)TiO<sub class="emphinferior">3</sub> (BCTZ32) lead-free piezoceramics. The piezoelectric coefficient, d<sub class="emphinferior">31</sub>, reaches a high value of 200 pC/N for BCTZ50 at room temperature which is comparable to the one of the soft PZT. This confirms the previously reported d<sub class="emphinferior">33</sub> for the same material. A useful way to achieve such performances at the expense of a smaller thermal budget is suggested, enabling better control of the ceramics composition and microstructure. Based on pyroelectric and ferroelectric hysteresis loops measurements, we show that such outstanding properties are likely due to the high flexibility of polarization under thermal and electric stresses.< Leer menos