Microstructure and ferroelectric properties of Nb2O5-modified BiFeO3-BaTiO3 lead-free ceramics for energy storage

The effects of Nb2O5 addition on microstructures, dielectric breakdown strength, and energy storage properties of BiFeO3-BaTiO3 (BF-BT) ceramics were investigated. X-ray diffraction patterns suggested a perovskite pseudocubic structure when the addition content was less than 3 mol%. The electrical resistivity of 1 mol% Nb2O5-doped BF-BT ceramic was increased by approximately six orders of magnitude compared to the corresponding undoped composition. The dielectric breakdown strength was enhanced with increasing Nb2O5 content and reached a maximum value at the composition with 3 mol% Nb2O5, with a maximum discharge energy density of 0.71 J/cm(3) at 90 kV/cm. This observation suggests that Nb-doped BF-BT ceramics can be considered as a potential lead-free system for energy storage applications. (C) 2014 Elsevier B.V. All rights reserved.