Optical and dielectric study of strontium modified barium zirconium titanate ceramic prepared by high energy ball milling

Abstract

Strontium modified barium zirconium titanate with general formula Ba_1−xSr_xZr_0.05Ti_0.95O₃ ceramics have been prepared by solid state and high energy ball milling technique. The X-ray diffraction and Rietveld refinement studies show that all the compositions have single phase symmetry. The composition BaZr_0.05Ti_0.95O₃ shows orthorhombic symmetric with space group Amm2. The structure changes from orthorhombic to tetragonal with strontium doping up to x = 0.3 and with further addition, changes to cubic. The scanning electron micrographs show that the grain size decreases with increase in strontium content. The temperature dependent dielectric behavior shows three phase transition in the parent material which merges with an increase in Sr content. The transition temperature and dielectric constant decreases with an increase in Sr concentration. The phase transition becomes more diffused with increment in doping concentration. The ferroelectric behavior of the ceramics is studied by the hysteresis loop. The optical behavior is studied by the UV–visible spectroscopy and found that the optical band gap increases with Sr concentration.