Effect of V2O5 on the sintering behavior, microstructure, and electrical properties of (Na0.5K0.5)NbO3 ceramics

Lead-free piezoelectric ceramics V₂O₅-doped (Na_0.5K_0.5)NbO₃ (abbreviated as NKN-V) has been successfully prepared by press-less sintering through the careful control of processing conditions. The sintering behavior , phase structure and electrical properties of the V₂O₅-doped NKN ceramics were investigated. Results show that with the introduction of 0.6 mol% V₂O₅, the NKN ceramics reaching the maximum value of 4.46 g/cm at the 1060degC and therefore exhibiting enhanced electric properties. But when the V₂O₅ content continued increasing, the density became lower possibly due to the appearing of the secondary phase as detected by XRD analysis. The dielectric properties of 0.6 and 0.9 mol% V₂O₅ -doped NKN ceramics perform better than pure NKN ceramics. In addition, annealing processing was proved to be an effective technique to improve dielectric properties and reduce the leakage current density (J).