Temperature‐independent large strain with small hysteresis in Sb‐modified BNT‐based lead‐free ceramics

Chemically modified (typically, via B‐site doping by Nb and Ta) Bi0.5Na0.5TiO3 (BNT)‐based piezoelectric ceramics, which exhibit superior electro‐strain behaviors than their perovskite peers, suffer from high hysteresis and poor temperature stability. In this study, the rarely studied dopant Sb is found to be effective in overcoming these two drawbacks by expanding the ergodic relaxor region to a wider temperature range. Excellent electro‐strain (0.41%–0.46%) with reduced hysteresis (15%–20%) was observed over the temperature range of 40–120℃, with 12% variation of electro‐strain in Bi0.5(Na0.78K0.22)0.5Ti0.9925Sb0.0075O3 samples. These results suggest that compared to previously reported BNT‐based piezoelectric ceramics, Sb‐modified BNT‐based ceramics show higher potential for practical actuator applications.