Dielectric and piezoelectric properties of SrZrO3-modified (K0.45Na0.51Li0.04)(Nb0.90Ta0.04Sb0.06)O3 lead-free piezoceramics

Lead-free (1-x)(K0.45Na0.51Li0.04)(Nb0.90Ta0.04Sb0.06)O3−xSrZrO3 ceramics were fabricated by a conventional ceramic technique, and the effects of SrZrO3 content on crystal phases and electrical properties of the ceramics were investigated. No secondary phase was identified by XRD analysis, indicating that SrZrO3 has completely diffused into the lattice and formed the solid solutions. The Curie temperature TC kept almost unchanged while the polymorphic phase transition temperature TO-T shifted slightly toward lower temperature with the increasing SrZrO3 content. Anomalous broad dielectric relaxation was observed in the εr-T curves near TC when x≥0.006. The properties of the ceramics were improved by adding a small amount of SrZrO3. The optimum electrical performances of d33=210 pC/N, kp=0.318, kt=0.310 and ε33T/ε0=677 were obtained at x=0.003.