Effect of Dy substitution on structural and dielectric properties in Ba1−3xDy2xTi0.9Sn0.1O3

The complex perovskite oxides, Ba1−3xDy2xTi0.9Sn0.1O3, have been synthesized by a solid state reaction technique. The effect of the replacement of Ba2+ by Dy3+ in the A site on the structural and dielectric properties were investigated. The room temperature X-ray powder diffraction (XRD) study reveals that all the compositions were a single phase cubic perovskite structure. The lattice parameters of the prepared compositions have been obtained by the Rietveld method using a computer program. A scanning electron microscopy (SEM) study revealed a decrease in the grain size with increasing Dy3+ concentration. It has been is also found that the Curie temperature decreases while the dielectric constant increases with increasing of Dy3+ concentration. The temperature variation of the real permittivity gives evidence of the ferroelectric phase transition and of the relaxation behavior. With increasing Dy3+ concentration, the degree of diffuse phase transition was enhanced, and a linear reduction in the transition temperature was obtained.