Defect-dipole reconstruction enables balanced piezoelectricity and low dielectric loss in Ni2+/Nd3+ Co-doped PZT ceramics

Lead zirconate titanate (PZT)-based piezoelectric ceramics are key functional materials for ultrasonic transducers, where the balance between piezoelectric activity and dielectric loss directly determines the energy conversion efficiency and thermal stability of devices. However, a fundamental trade-off exists between these two properties, as enhancing piezoelectric performance is often accompanied by increased dielectric loss, resulting in excessive heat generation and degraded long-term reliability during high-power operation. Moreover, the microscopic mechanism governing the balance between piezoelectric and dielectric properties in multi-component co-doped PZT systems remains insufficiently understood. In this work, a defect-dipole reconstruction strategy is proposed by introducing Nd 3+ donor ions into Ni 2+ -modified PZT ceramics. The results demonstrate that this strategy enables a stable low dielectric loss (tanδ = 0.02-0.03) over a broad temperature range from room temperature to 300 °C while maintaining desirable piezoelectric activity. The optimized NNPZT2 composition achieves a high piezoelectric coefficient (d 33 ) of 260.6 pC/N. Such balanced electrical performance originates from the synergistic regulation of defect chemistry and polarization behavior: Nd 3+ incorporation is proposed to destabilize the ordered Ni 2+ -induced defect-dipole configuration through donor-acceptor charge compensation and subsequently reconstructs a localized polarization state dominated by polar nanoregions (PNRs). This polarization reconstruction facilitates reversible polarization switching while suppressing oxygen-vacancy-related dielectric loss. This work provides new insights into donor-acceptor interaction-mediated defect regulation and polarization reconstruction in PZT ceramics, offering an effective strategy for designing high-performance piezoelectric materials with simultaneously low dielectric loss, improved thermal stability, and enhanced energy conversion efficiency for wide-temperature-range electromechanical applications.