Structural distortion and dielectric properties of Sr1−x(Na0.5Bi0.5)xBi2Nb2O9 (x=0.0, 0.2, 0.5, 0.8 and 1.0)

SrBi2Nb2O9 (SBN) powders with varying substitution of Sr by (Na0.5Bi0.5) were prepared by hydrothermal technique. It was observed that all the samples with Sr1−x(Na0.5Bi0.5)xBi2Nb2O9 (x=0.0, 0.2, 0.5, 0.8 and 1.0) formula had a single phase orthorhombic structure. Effects of (Na0.5Bi0.5) doping on the structural and dielectric properties of ferroelectric ceramics are discussed. Decreased orthorhombic distortion was observed for doped SBN. The structure attains more orthorhombicity with doping (Na0.5Bi0.5). The Curie temperature (TC) increases from 429 to 734°C when x increases from 0.0 to 1.0. This could be interpreted in terms of the change in the unit cell size. It was also noticed that the dielectric loss is significantly reduced with increasing addition of (Na0.5Bi0.5). Mean grain size for solid solutions was measured. A grain growth from 42 to 125nm was observed.