Papers by Keyword: Bismuth Layer Structure

Abstract: 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 (Tc), enhanced the remnant polarization (2Pr) and decreased the coercive field (Ec) 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: d33 = 21 pC/N, 2Pr = 14.3 μC/cm2, Tc = 251°C, εr = 376, tanδ = 1.8%.

Abstract: Sr2Bi (4-x/3) Ti (5-x) VxO18 (x = 0.0-0.06) (SBTV) ceramics were prepared by a solid-state reaction method, and the ferroelectric and dielectric properties of the ceramics were investigated with respect to the amount of V deficiency. XRD analysis indicated that the oxide compounds were Aurivillius phases. The Curie temperature of SBTV ceramics was improved by doping of certain amount of V. The V deficiency also led to a steady increase in the density together with a decrease in the coercive field. For the ceramics with x = 0.06, the properties become optimum: d33 = 19 pC/N, Tc = 306oC, Ec = 43.7 KV/cm.