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

Abstract

Well-sintered (Na(0.5)K(0.5))NbO(3)-x mol% V(2)O(5) ceramics (abbreviated as NKN-V) with fine electrical properties were successfully prepared by conventional solid-state reaction through the careful control of processing conditions. The sintering behavior, phase structure, and electrical properties of the V(2)O(5)-doped NKN ceramics were investigated. Results show that when the V(2)O(5) content is 0.6 mol%, the NKN ceramics attained the maximum density of 4.46 g/cm(3) (about 98.9% of the theoretical density) at 1060 degrees C, and therefore possessed enhanced electrical properties. But when the V(2)O(5) content continued increasing, the density decreased. The secondary phase (Na(2)V (6)O(16)) could be detected by XRD analysis in all samples except x = 0 mol%. The Curie temperature of the NKN-based materials was found to decrease with the increase of V(2)O(5). The dielectric properties of NKN ceramics doped with 0.6 and 0.9 mol% V(2)O(5) were better than that of pure NKN ceramics. In addition, annealing treatment was proved to be an effective technique for improving dielectric properties and reducing the leakage current density.