Dielectric, conductivity and piezoelectric properties in (0.67-x)BiFeO3-0.33BaTiO3-xSrZrO3 ceramics

A new type of (0.67-x)BiFeO3-0.33BaTiO(3)-xSrZrO(3) (x = 0.00, 0.02, 0.04, 0.06, 0.08 wt%, abbreviated as SZ100x) ternary lead-free relaxation ceramic was prepared by a conventional mixed-oxide sintering method. The surface texture, dielectric, impedance, electrical conductivity and piezoelectric were studied in detail. It was found that three kinds of compounds are completely dissolved into a single structure with a pseudo-cubic (Pc) phase. Besides, scanning electron microscopy figures indicated that proper doping can make the ceramic system more compact while excessive SrZrO3 content would cause abnormal growth of the grain. In addition, the analysis of dielectric temperature spectra shown that the dielectric peaks gradually widen with an increase in x and the x = 0.04 sample has the strongest relaxation characteristics. Importantly, doping of SrZrO3 can greatly improve the impendence and electrical insulation characteristics. Besides, high strain value of 0.24% with the normalized strain value of 400 pm/V was obtained at x = 0.04, which was related to the relaxation response of the polar nanoregion under electric field.