Synergistic enhancement of Curie temperature and piezoelectric properties in PIN‒PMN‒PT transparent ceramics

Transparent piezoceramics integrating a high piezoelectric coefficient ( d 33 ) and electromechanical coupling factor ( k p ) are very important to the applications of electro‐acoustic and electro‐optical sensors. Simultaneously achieving both high Curie temperature and superior piezoelectric properties for 25 Pb(In 1/2 Nb 1/2 )O 3 ‒41 Pb(Mg 1/3 Nb 2/3 )O 3 ‒34PbTiO 3 (PIN‒PMN‒PT) ceramics is a challenge, although they exhibit good optical transmittance. Herein, dual rare‐earth elements Sm 3+ /La 3+ co‐doping method is employed to optimize the performance of 25PIN‒41PMN‒34PT ceramics. The 0.5% Sm/1.5% La co‐doping composition exhibits a superior high Curie temperature ( T C = 172°C) with exceptional piezoelectric response ( d 33 = 730 pC/N) and high electromechanical coupling coefficient ( k p = 0.62), achieving a breakthrough in synergistic enhancement of both T C and piezoelectric properties. The results demonstrate that optimized Sm 3+ /La 3+ co‐doping simultaneously induces refined domain configurations and suppresses oxygen‐vacancy formation, resulting in significantly improved piezoelectric properties. This work provides an efficient strategy for developing high‐performance transparent piezoceramics in next‐generation electro‐acoustic and electro‐optical sensor applications.