Ferroelectric and dielectric properties of 0.6SrBi 2Nb 2O 9-0.4BiFeO 3 thin films

Abstract

In this paper, we report the formation and ferroelectric properties of 0.6SrBi 2Nb 2O 9-0.4BiFeO 3 thin films with layered perovskite structure on Pt/Si substrate, which were prepared via a sol-gel route. The single-phase layered perovskite structure was developed at 750 °C, while to a high annealing temperature, such as at 800 °C, generated a fluorite structure due to the evaporation of Bi 2O 3. The 0.6SrBi 2Nb 2O 9-0.4BiFeO 3 film annealed at 750 °C demonstrated a dense structural morphology and exhibited the wanted ferroelectric and dielectric properties. When measured at an applied field of 225 kV/cm, it showed a remanent polarization (2P r) of 5.5 μC/cm 2 and a coercive field (2E c) of 65.6 kV/cm, respectively, together with a leakage current density of 5×10 -8 A/cm 2 at 125 kV/cm. Its dielectric constant and dielectric loss factor were ∼130 and ∼2%, respectively, measured at the frequency of 1 MHz and at room temperature. © 2004 Elsevier B.V. All rights reserved.