Relaxor behaviour of (Ba0⋅5Sr0⋅5)(Ti0⋅6Zr0⋅4)O3 ceramics

Abstract

Ba0⋅5Sr0⋅5Ti0⋅6Zr0⋅4O3 ceramic has been prepared through solid state reaction route. X-ray diffraction shows that the sample has cubic perovskite structure with space group Pm–3m at room temperature. Temperature dependent dielectric study of the ceramic has been investigated in the frequency range 50 Hz– 1 MHz. The density of the sample is determined using Archimedes’ principle and is found to be ~99% of X-ray density. The dielectric study revealed diffuse phase transition of second order. A broad dielectric anomaly coupled with the shift of dielectric maxima toward a higher temperature with increasing frequency indicates the relaxor-type behaviour in the ceramics. The index of relaxation (γ) and the broadening parameter (Δ) were estimated from a linear fit of the modified Curie–Weiss law. The value of γ ~ 1⋅72 indicates the strong relaxor nature of the ceramic. A remarkably good fit to the Vogel–Fulcher relation further supports such a relaxor nature.