Enhanced piezoelectric and ferroelectric properties of Nb₂O ₅ modified lead zirconate titanate-based composites

The addition of ZnO nanowhiskers (ZnO_w) in lead zirconate titanate (PZT) matrices results in reinforced composite materials but deteriorates their electrical properties. In this study, novel piezoelectric PZT/ZnO_w composites modified with Nb₂O₅ were successfully fabricated using solid-state sintering method. The experimental results showed that the addition of 0.5 wt% Nb₂O₅ resulted in highly dense and homogenous PZT composites after sintering at 1150°C, with good piezoelectric and ferroelectric properties similar to pure PZT, specifically piezoelectric constant d₃₃=665 pC/N, electromechanical coupling factor k_p=0.7, relative dielectric constant ε=5048, and remnant polarization P_r=30.2 μC/cm². The "soft effect" of Nb⁵⁺ ions, reflected in the improvement of the aforementioned properties, is attributed to the accommodation of Nb⁵⁺ ions at the B sites of the lattice of PZT. Compared with the PZT/ZnO _w reinforced composites, the mechanical properties were slightly improved by adding 0.5 wt% Nb₂O₅, where flexural strength Ï_f of 128 MPa and fracture toughness K_IC of 1.46 MPa·m^1/2 were measured.