Study on Ferroelectric and Dielectric Properties of Zr-Doped Sr2Bi4Ti5O18 Ceramics

Zr-doped Sr2Bi4Ti5O18 (SBTi) bismuth layer-structured ferroelectric ceramics were prepared and studied. XRD patterns revealed that all the ceramic samples were single phase compounds. SEM images showed that dense microstructures with uniform gain size were obtained in all samples. The effects of Zr4+ doping on the dielectric, ferroelectric and piezoelectric properties of SBTi ceramics were also investigated. It was found that Zr4+ dopant gradually decreased the Curie temperature (T-c), enhanced the remnant polarization (2P(r)) and decreased the coercive field (E-c) of SBTi ceramics. Furthermore, the piezoelectric properties of the SBTi ceramics were improved by enlarging the content of Zr. The SBTi ceramics with 4 mol% of Zr4+ dopant exhibited good electrical properties: d(33) = 21 pC/N, 2P(r) = 14.3 mu C/cm(2), T-c = 251 degrees C, epsilon(r) = 376, tan delta = 1.8%.