Abstract

The effect of A-site substitution of Ce 3+ in tungsten bronze structured PBN ceramics with the general formula, Pb (x-3y/2) Ce yBa (1-x)Nb 2O 6 and the stoichiometric chemical formula, Pb (0.65-3y/2) Ce yBa 0.35Nb 2O 6, where y=0, 2, 4, 6, 8 and 10 mol% ceramic compositions synthesized through solid state reaction method are reported. The X-ray diffraction studies exhibited the presence of an orthorhombic phase, and its intensity increased with the increasing Ce 3+ content up to y = 6 mol% or A 3 composition. The lattice parameters, unit cell volume and density as a function of Ce 3+ concentration are discussed. It is observed that increasing Ce 3+ content in A-site influenced the dielectric properties. The optimum dielectric properties of room temperature dielectric constant (e RT) and dielectric maximum (e T c) are observed in y = 6 mol% or A 3 composition while Curie temperature (T c) and dielectric loss (tan d) constantly decreased from undoped to y = 10 mol%, and thus A 3 composition or 6 mol% Ce modified tungsten bronze structured-PBN could be suitable for capacitor applications. © Springer Science+Business Media, LLC 2008.