Diffuse phase transition behavior of dysprosium doped barium titanate ceramic

Abstract

The effect of dysprosium (Dy) doping on the structural and dielectric properties of barium titanate (BaTiO3) ceramic has been studied. Dysprosium-doped barium titanate (BT) with general formula Ba1-xDy2x/3TiO3 (x = 0.0-0.1) is prepared through solid state reaction route. The XRD pattern reports the single phase tetragonal structure up to x = 0.025 with space group of P4mm and a secondary phase is observed for higher concentration of Dy. The Raman study of Ba1-xDy2x/3TiO3 (x = 0.00, 0.01, 0.025) also reveals that the ceramic is showing tetragonal symmetry and with an increase in Dy doping the tetragonal phase is moving toward more symmetric phase i.e. cubic pm3m. The surface morphology of the sintered pellets shows a compact and homogeneous grain distribution with a decrease in grain size as the Dy content increases. The temperature and frequency dependency dielectric study of the ceramic compositions (x = 0.00, 0.01, 0.025) are studied to show the effect of Dy ion on the A site of BaTiO3 perovskite ceramic. The dielectric constant decreases with increase in Dy content. The dielectric diffusivity increases with increase in doping concentration. The P-E hysteresis loop confirms the ferroelectric behavior of the sample with decrease in remanent polarization and increase in coercive field.