Structure, dielectric and electrical properties of cerium doped barium zirconium titanate ceramics

Abstract

Rare-earth doped barium zirconium titanate (BZT) ceramics, Ba(Zr0.25Ti0.75)O3+xCeO2, (x=0–1.5at%) were obtained by a solid state reaction route. Perovskite-like single-phase compounds were confirmed from X-ray diffraction data and the lattice parameters were refined by the Rietveld method. It is found that, integrating with the lattice parameters and the distortion of crystal lattice, there is an alternation of substitution preference of cerium ions for the host cations in perovskite lattice. Morphological analysis on sintered samples by scanning electron microscopy shows that the addition of rare-earth ions affects the growth of the grain and remarkably changes the grain morphology. The effect of rare-earth addition to BZT on dielectric and electrical properties is analyzed. High values of dielectric tunability are obtained for cerium doped BZT. Especially, the experimental results on the effect of the contents of rare-earth addition on the resistivity of BZT ceramics were investigated, demonstrating that the samples with x=0.4 and x=0.6 could be semiconducting in air atmosphere.