Influence of low sintering temperature on the structural, morphological, and dielectric properties of (Bi0.4Ba0.1)Na0.5TiO3 ceramics

Abstract

This paper presents the preparation of ceramics with (Bi_0.4Ba_0.1)Na_0.5TiO₃ via a conventional solid-state reaction method and their sintering at low temperatures of 850, 900, and 950 °C for 3 h, respectively. Bi₂O₃ and Na₂O₃ were used to suppress the volatility of Bi and Na ions during the sintering of (Bi_0.4Ba_0.1)Na_0.5TiO₃ ceramics. X-ray diffraction (XRD), Scanning electron microscope (SEM), and an LCR meter were used to analyze these ceramics' structural, morphological, and dielectric properties. Rhombohedral crystal lattice (with space group R3c) is confirmed by Rietveld’s refinement of the XRD pattern. W–H plots show an increase in crystallite strain from 0.77 × 10^–3 to 1.5 × 10^–3 due to a decrease in average crystallite size from 133.32 to 119.52 nm. With an increase in sintering temperature, the grain size increased from 0.55 to 2.30 μm on average based on SEM images. Dielectric spectra revealed that the magnitude of the dielectric constant (ε) decreases with frequency increase and is explained by Maxwell–Wagner’s Model. The ferroelectric phase transition temperature is shifted to a higher temperature, which makes the material feasible for energy storage applications.