Characterization of high-field properties of 0.28PIN-0.42PMN-0.30PT single crystal/epoxy 1-3 composite for acoustic transducer applications

The (1-x-y)Pb(In1/2Nb1/2)O3-yPb(Mg1/3Nb2/3)O3-xPbTiO3 (PIN-PMN-PT) single crystal/polymer composites have been widely employed in high-performance acoustic transducers, while the high-field properties charac-terization of the piezoelectric composites is still relatively lacking. In this research, a high-field impedance spectrum characterization system was used to investigate high-field properties of a 0.28PIN-0.42PMN-0.30PT single crystal/epoxy 1-3 composite. The impedance spectra of the PIN-PMN-PT composite thin plate in thick-ness resonance mode were measured under the constant-voltage mode with different voltage amplitudes. By measuring the resonance and antiresonance frequencies, the ac electric field dependence of the properties of the composite plate were investigated. The experimental results showed that both the resonance frequency and antiresonance frequency decreased gradually as the driving electric field was increased from 5.13 Vpp/mm to 51.3 Vpp/mm, but the impedance spectra did not become distorted in this electric field range. By analyzing the impedance spectra, it was found that the electromechanical coupling factor kt and the piezoelectric coefficient d33 increased with the rising field, while the elastic stiffness cD33 and the mechanical quality factor Q both decreased with the field. Under a high ac field, compared to PZT8 1-3 piezoceramic composites, the PIN-PMN-PT single crystal 1-3 composites were found to have more superior electromechanical performances such as higher kt and d33 values. These results are helpful for the design and application of acoustic transducers.