Strontium-titanate-doped lead metaniobate ferroelectric thin films

Abstract

Ferroelectric polymorph of lead metaniobate (PbNb2O6) exhibits an orthorhombic structure, which is metastable at room temperature and can only be obtainable by quenching from high temperatures (∼1200°C). In this letter, we report a ferroelectric PbNb2O6 thin film doped with SrTiO3 (Pb0.95Sr0.05(Nb 2)0.98Ti0.05O6) with orthorhombic structure on Pt/Ti/Si substrate, which was prepared via a sol-gel route. The orthorhombic structure was developed at 900°C at a normal heating rate of 5°C/min and cooling rate of 10°C/min. The PbNb2O6 film exhibited a remanent polarization (Pr) of 12.3μC/cm 2 and a coercive field (Ec) of 39 kV/cm, respectively, when measured at an applied field of 143 kV/cm. The leakage current density was 1.02×10-5A/cm2 at 100 kV/cm. The room-temperature dielectric constant and dissipation factor was stable (∼325 and ∼1.5%, respectively) over a frequency range of 1 kHz to 1 MHz. © 2002 American Institute of Physics.