Enhanced insulation resistance and electrical properties of BiFe1-x(Zn0.5Ti0.5)xO3-BaTiO3 lead-free piezoceramics

The phase structure, microstructure and electrical properties of 0.7BiFe(1-x)(Zn0.5Ti0.5)(x)O-3-0.3BaTiO(3) (0.00 <= x <= 0.07) (BFZTx-BT) ceramics prepared via a conventional solid-state reaction method were studied by emphasizing the effect of Bi(Zn0.5Ti0.5)O-3. BFZTx-BT ceramics show coexisting rhombohedral-pseudocubic (R-PC) phase when 0.00 <= x <= 0.05 and a single PC structure at x = 0.07. The fraction of R to PC phase (C-R/C-pc) calculated by Rietveld refinement was 53/47, 51/49, 21/79, 14/86 at x = 0.00, 0.01, 0.03 and 0.05, respectively. Adding (Zn0.5Ti0.5)(3+) leads to an enhanced insulation resistance 130 G Omega.cm for x = 0.05 composition under 1 kV/mm, which is one order of magnitude higher than that at 0.00 <= x <= 0.03. Owing to the synergy effects of polarization performance and proper CR/Cpc fraction, optimum electrical properties of BFZTx-BT ceramics d(33) = 135 pC/N, T-c = 482 degrees C, k(p) = 25% were attained at x = 0.05. Our result indicates that the formation of ternary solid solution is an effective and convenient strategy to enhance the electrical performance of BF-BT based piezoceramics by tailoring insulation resistance along with the phase structure.