Dielectric properties and energy storage density in ZnO-doped Ba0.3Sr0.7TiO3 ceramics

ZnO additions to Ba0.3Sr0.7TiO3 ceramics have been studied in order to determine the role of this dopant on dielectric property and energy storage density development. The temperature and frequency dependences of dielectric constant, the breakdown strength, and the dielectric dissipation were measured. The dependence of dielectric constant to applied DC field was used to evaluate the energy storage densities. The crystalline structure and morphology were also investigated by XRD and SEM, respectively. Experimental results show that the stored energy density for the sample with 1.6 wt% ZnO addition is the highest among all the compositions. At 40 kV mm(-1) electric fieled, its stored energy density can reach 3.9 J cm(-3). Moreover, the ceramic with this composition has higher dielectric constant and breakdown strength, lower loss and dependency characteristic of dielectric constant to applied electric field. (C) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved.