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Alternating current polarization (ACP) has been demonstrated to enhance the performance of 1-3 piezoelectric single crystal composites (PSCCs), compared to direct current polarization (DCP). However, the scaling effect and temperature stability of PSCCs under different polarization modes, which are of significance to practical applications, have rarely been studied. Here, we compared and analyzed the thickness and temperature-dependent properties of PSCCs under ACP and DCP. The results indicated that ACP PSCCs have improved piezoelectric, electromechanical coupling, and dielectric properties. There were scaling effects for PSCCs with thickness below 400 μm. Compared to high-thickness PSCCs, the piezoelectric coefficient (d33), free dielectric constant ( ε 33 T ε 0 ) as well as thickness electromechanical coupling factor (kt) of low-thickness samples were inferior and the corresponding performance enhancements under ACP were also relatively low. In contrast, the clamped dielectric constant ( ε 33 S ε 0 ) did not show significant thickness correlation. As for temperature stability, all performances of PSCCs improved with increase in temperature and the performance enhancement with temperature change was not dependent on the polarization conditions. This work provides reference significance of selecting appropriate polarization for PSCCs, thus benefiting the design and preparation for transducers. [ABSTRACT FROM AUTHOR]

Pb-based relaxor piezoelectric single crystal composites (PSCCs) have attracted widespread attention for improving the bandwidth and sensitivity performance of acoustic transducers due to their excellent electromechanical and piezoelectric properties. Alternating current polarization (ACP) has been proven as an effective method for enhancing the dielectric and piezoelectric properties of relaxor-PbTiO3 single crystals. Herein, we investigated the effects of the amplitude, frequency, and cycle number of the poling electric field on the piezoelectric and dielectric performances of PSCCs and obtained the optimum poling condition of ACP. Compared with the traditional direct current poling method, both the dielectric permittivity ( ε 33 T / ε 0 ) and piezoelectric coefficient ( d 33 ) of the AC-poled PSCCs were both increased by up to 20%. Notably, the ACP PSCC with a volume fraction of 60% exhibited a high d 33 of 1610 pC/N, which is superior to values previously reported for PSCCs. This work provides an alternative strategy for enhancing the properties of PSCCs and may contribute to the further development of piezoelectric applications. [ABSTRACT FROM AUTHOR]