Performance enhancements of Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ single crystal/epoxy 1-3 composite by alternating current polarization

Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) single crystal/epoxy 1-3 piezoelectric composite was designed to decrease acoustic impedance and to improve the electromechanical property, which was vital to the ultrasound transducers. The piezo-/dielectric properties of the PMNT/epoxy 1-3 composites prepared by the different poling methods were measured. It was found that piezoelectric coefficient d(33), dielectric constant epsilon(T)(33)/epsilon(0), and electromechanical factor kt of composites exhibited the significant increases of 16.41%, 6.89%, and 1.97% under optimized alternating current polarization (ACP), compared with those of the samples using direct current polarization (DCP). The domain patterns suggested that the remarkable regular striped domain and high domain wall density of the ACP sample could result in performance enhancements. The ACP composite-based transducer's bandwidth (BW) and relative sensitivity (RS) were improved by 6.27% and 1.93 dB. These results indicated that the ACP effectively enhances the piezoelectric composite's performances, and BW and RS of the transducer based on ACP piezo-electric materials are improved simultaneously.