Effect of gadolinium on the dielectric and pyroelectric behavior of Ba(Zr0.52Ti0.48)O-3 ceramics

Abstract

The microstructure, dielectric and pyroelectric properties of pure and Gd3+- doped barium zirconium titanate in the form of Ba(Zr0.52Ti0.48)O-3 and (Ba1-xGdx)(Zr0.52Ti0.48)O-3 (x = 0.1 and 0.2) were studied in this work. These ceramics were synthesized from solid state reaction method at 1050 degrees C. The patterns obtained from x-ray diffraction revealed the formation of perovskite phase with tetragonal crystal symmetry. As the concentration of Gd-ion increased, the value of temperature dependent dielectric constant varied whereas the Curie temperature of the ceramics shifted towards higher temperature side. The ceramic sample doped with Gd = 0.1 exhibited diffuse phase transition whereas other one showed relaxor like behavior. This result is attributed to unsystematic decrease in average grain size due to doping of Gd-ions. The temperature dependent pyroelectric current was negative at similar to 150 degrees C for pure ceramics and at similar to 200 degrees C for Gd-doped ceramics. This negative pyroelectric current represents the primary pyroelectric effect within that temperature.