Structural, optical dielectric and ferroelectric properties of double perovskite BaBiFeTiO6

Abstract

The polycrystalline BaBiFeTiO6 (BBFTO) ceramic is synthesized by a high-temperature solid-state reaction route. According to X-ray Diffraction (XRD) and Rietveld refinement analysis, the compound is cubically ordered and belongs to the Fm-3 m space group. The universal Scherrer's formula was used to calculate the average crystallite size of 55 nm. Scanning electron micrographs (SEM) show non-uniform distributions of dense micro grains of average grain size of 150 nm. Tauc equation and diffuse reflection spectra were used to determine the absorbance and reflectance optical bandgap as 2.15 eV and 2.25 eV, which supports the possible usage in photocatalytic applications. The P-E hysteresis loop revealed the compound has room temperature (RT) ferroelectric property with higher remnant polarization, 2Pr = 1.93µC/cm2, thus can be useful in ferroelectric memory devices. The material experiences ferroelectric to a paraelectric phase transition, Td > 410 °C, Curie point, Tc > 490 °C and RT dielectric constant, ɛr = 1149 at 100 Hz, hence can be used as a dielectric material in multi-layered ceramic capacitors.