Enhanced room temperature relative permittivity and low dielectric loss ferroelectric double perovskite for energy storage applications

Abstract

The polycrystalline ceramic oxide, BaBi1.2Fe0.8TiO6 is synthesized by a mixed oxide method at 1000 °C. XRD and Rietveld's analysis suggests a tetragonal system and P4mm space group. The closely spaced dense micro grains of various shapes and sizes in scanning electron micrograph (SEM) image support the polycrystalline single-phase compound. The UV–Visible spectroscopy results in a convenient value of threshold wavelength (610 nm), absorption bandgap energy (2.23 eV), and reflectance bandgap energy (2.31 eV) which are good responses to the IR and visible range and its possible application in photocatalytic devices. The room temperature (RT) polarization loop shows non-zero remanent polarization, i.e. ferroelectric property of the compound. Relatively higher room temperature dielectric permittivity (ɛr = 2455) with low loss tangent (tanδ) = 0.247 at 100 Hz, phase transition (Td > 200 °C), and Curie (Tc > 470 °C) temperature values are supporting to be as good dielectric material for ceramic capacitors. Transport property shows lower RT current density is in order of 1E-9 at 300 V/cm. The compound follows the Arrhenius equation and results in imminent values of activation energy in ac conductivity (Ea = 0.847 eV at 100 Hz) and dc conductivity (Ea = 0.838 eV) analysis. Based on the results, the present compound is likely to be used as a dielectric material in ceramic capacitors, energy and memory storage devices, and photocatalytic devices.