Large electrostrains with high temperature stability and low hysteresis are essential for applications in high-precision actuator devices. However, achieving simultaneously all three of the aforementioned features in ferroelectric ceramics remains a considerable challenge. In this work, we firstly report a high unipolar electrostrain (0.12% at 60 kV/cm) in (1–x)NaNbO₃-x[(Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃] (NN-xBCZT) ferroelectric polycrystalline ceramics with excellent thermal stability (variation less than 10% in the temperature range of 30–160 °C) and ultra-low hysteresis (<6%). Secondly, the high-field electrostrain response is dominated by the intrinsic electrostrictive effect, which may account for more than 80% of the electrostrain. Furthermore, due to the thermal stability of the polarization in the pure tetragonal phase, the large electrostrain demonstrates extraordinarily high stability from room temperature to 140 °C. Finally, in-situ piezoelectric force microscopy reveals ultra-highly stable domain structures, which also guarantee the thermal stability of the electrostrain in (NN-xBCZT ferroelectrics ceramics. This study not only clarifies the origin of thermally stable electrostrain in NN-xBCZT ferroelectric perovskite in terms of electrostrictive effect, but also provides ideas for developing applicable ferroelectric ceramic materials used in actuator devices with excellent thermal stability.

具有高温稳定性和低滞后的大电应变对于高精度执行器设备的应用至关重要。然而，在铁电陶瓷中同时实现上述所有三个特征仍然是一个相当大的挑战。在这项工作中，我们首先报道了在 (1- x )NaNbO ₃ - x [(Ba _0.85 Ca _0.15 )(Zr _0.1 Ti _0.9 )O ₃ ] (NN- xBCZT) 铁电多晶陶瓷，具有出色的热稳定性（在 30–160 °C 的温度范围内变化小于 10%）和超低滞后 (<6%)。其次，高场电应变响应以本征电致伸缩效应为主，可能占电应变的 80% 以上。此外，由于在纯四方相中极化的热稳定性，大的电应变在室温到 140°C 表现出非常高的稳定性。最后，原位压电显微镜揭示了超高度稳定的畴结构，这也保证了电应变在 ( NN- xBCZT铁电陶瓷。该研究不仅从电致伸缩效应的角度阐明了 NN - x BCZT 铁电钙钛矿中热稳定电应变的起源,同时也为开发用于致动器设备的具有优异热稳定性的适用铁电陶瓷材料提供了思路。