The enhanced piezoelectric property of (Li,K,Na)(Nb,Ta)O₃ lead-free ceramics induced by rare earth oxide doping

The ions doping engineering has already been proved to be an effective approach of adjusting the intrinsic properties of perovskite structured materials and even realizing some new functionality. The polymorphic phase transition effect was put forward to elucidate the enhanced ferroelectric and piezoelectric properties in (K,Na)NbO₃-based materials. In current research, Li-Ta modified (K,Na)NbO₃ lying in composition region of the coexistence structure was selected as target materials, and Ce₂O₃ was chose as dopant in order to reveal the effect of ion doping on the target materials. Owing to the sensitive energy state in the coexistence phase structure, an obvious phase evolution from orthorhombic to tetragonal would be brought about by the doping of Ce₂O₃. When the doping amount was 0.5% mol, the enhanced ferroelectric property (the remnant polarization of P_r = 21.8 μC/cm²), piezoelectric property (the piezoelectric coefficient of d₃₃ = 272 pC/N) and field-induced property (0.13@4 kV/mm) could be achieved.