Performance Enhancement of Piezoelectric Single Crystals Through Combination of Alternating-Current Poling and Direct-Current Poling

Highlights: What are the main findings? A new approach to polarize the PMN-PT single crystals was proposed in the work. There were two optimal polarization windows in the new approach experiment’s result. What are the implications of the main findings? The multi-peak phenomenon needs to be explained in theory. The performance enhancement of PMN-PT single crystals can be customized in this way. Alternating-current poling (ACP) is becoming a mainstream method because of its stronger ability in promoting the piezoelectric performance of ferroelectric single crystals than that of direct-current poling (DCP). A novel approach was developed by incorporating alternating-current poling and direct-current poling as modified alternating-current poling (MACP). According to the comparison of performance differences between AC-poled and DC-poled single crystals, the properties of MACP single crystals under specific conditions were systematically investigated. The improvement of single crystal performance by MACP is manifested by the multi-peak increase in piezoelectric coefficient ((Formula presented.)) and relative dielectric permittivity ((Formula presented.)), and the coupling factor ((Formula presented.)) value under higher DC bias is higher than that under DC polarization, rather than a direct superposition of DCP and ACP. Two optimal polarization windows were found: 0.2–0.25 kV/mm and 0.35–0.6 kV/mm. Compared with DCP, MACP increases the (Formula presented.), (Formula presented.) and (Formula presented.), of single crystals by up to 45.67%, 21.62%, and 24.54%, respectively. This significant performance improvement, combined with its complexity, provides a new direction for customizing the performance of single crystals.