Diffusion phase transition and ferroelectric properties of 0.92K_(0.5)Na_(0.5)NbO_3-(0.08 -x)Bi_(0.5)Li_(0.5)TiO_3-xBaZrO_3 ceramics

摘要

0.92K_(0.5)Na_(0.5)NbO_3-(0.08 -x)Bi_(0.5)Li_(0.5)TiO_3-xBaZrO_3(KNN-BLT-BZ) lead-free piezoelectric ceramics were fabricated by traditional ceramics process. XRD results showed that complete solid solutions with mixed phases of rhombohedra and tetragonal were observed. Diffusion phase transitional behavior, dielectric properties and ferroelectric properties of the KNN-BLT-BZ ceramics were investigated. It was found that the cubic-tetragonal phase transition temperature {Tc) slightly decreased as the amount of BaZrO_3 was increased. A morphotropic phase boundary (MPB) between rhombohedral and tetragonal ferroelectric phases was identified in the composition range of 0.04 < x < 0.06. Furthermore, good ferroelectric properties were also found in this composition range, with P_r of 14.5μC cm~(-2) and E_c of 1.95 kV mm~(-1) for the sample with x = 0.04.