Enhanced piezoelectric performance of textured ceramics based on AC polarization technology for ultrasonic transducer

Piezoelectric materials serve as the core component of ultrasonic transducers, where advancing system capabilities necessitates continuously improved performance. To this end, alternating current polarization (ACP) was employed to enhance the piezoelectric properties of [001]_c-textured Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT) ceramics. Compared to samples prepared via direct current polarization, ACP-textured ceramics achieved superior performance: a piezoelectric coefficient (d ₃₃) of ∼1200 pC/N, a relative permittivity (ε_r) of ∼2953, and an electromechanical coupling factor (k _t) of ∼0.67. This enhancement is attributed to a more uniform domain structure and a higher density of domain walls induced by the ACP process. Furthermore, a 1–3 composite 5 MHz transducer fabricated from these ACP-textured ceramics demonstrated a broad bandwidth of ∼141% and a low insertion loss of −12 dB, representing leading performance for ceramic-based transducers operating in the 2–5 MHz range. This work highlights the potential of ACP for developing high-performance piezoelectric materials essential for future broadband ultrasonic transducers.