Brief Review of Lead-Free Piezoelectric Ceramics for High-Power Applications

Abstract

Lead-free piezoelectric ceramics have gained significant attention as environmentally friendly alternatives to leadbasedmaterials such as Pb(Zr,Ti)O3 (PZT) for high-power applications. This review focuses on three prominent lead-free ceramicsystems: BaTiO3 (BT), Bi0.5Na0.5TiO3 (BNT), and (Na0.5K0.5)NbO3 (NKN). BT-based ceramics offer excellent piezoelectric propertiesbut are limited by their low Curie temperatures, which has been addressed through doping and sintering aids such as Li2O. BNT-basedceramics exhibit high thermal stabilities and tunable electromechanical properties; however, challenges remain because of their relativelylow piezoelectric coefficients. NKN-based ceramics demonstrate outstanding mechanical quality factors (Qm) and high Curietemperatures, with significant performance improvements achieved through CuO doping and co-doping with other oxides. Despitethese advancements, issues such as thermal stability, alkaline element volatility, and limited d33 still need to be resolved. Continuedprogress in doping strategies, microstructural control, and advanced processing techniques will be crucial to fully unlock the potentialof lead-free piezoelectric ceramics for high-power applications.