Structural and Electrical Properties of Bismuth Sodium Titanate (Bi\(_0\)\(_.5\)Na\(_0\)\(_.5\)TiO\(_3\)) Ceramics

Abstract

Recent developments in high-temperature technology have increased the demand for dielectric ceramics with durable dielectric properties. Furthermore, dielectric ceramics are finding enormous applications in various energy storage systems. To address these requirements, this study mainly is focused on imparting relaxor characteristics to Bismuth Sodium Titanate Bi_0.5Na_0.5TiO₃ (BNT) ceramics. A single-phase lead-free (BNT) perovskite ferroelectric ceramic was successfully synthesized via the solid-state reaction method. This study offers an in-depth examination on the structural and electrical characteristics of the BNT ceramic. Through phase analysis utilizing Rietveld refined X-ray diffraction, it was determined that the crystal structure of the BNT ceramic is single-phase and possesses rhombohedral (R3c) symmetry. Raman spectroscopy measurements further support the rhombohedral structure of BNT, as indicated by the presence of multiple peaks originating from the TiO₆ octahedra. The ferroelectric nature of the BNT sample was confirmed through hysteresis loop measurements of polarization vs. electric field (P-E). The BNT sample exhibited characteristic values of remnant polarization (P_r) and coercive field (E_c), which were measured to be 1.63 \(\mu\)C/cm² and 29.91 kV/cm, respectively. The ferroelectric phase transition was also observed in temperature-dependent dielectric studies, with a transition temperature of 323 °C. Remarkably, the material displayed low values of tan\(\delta\) even at high temperatures, such as 500 °C, at a frequency of 1 MHz. This suggests that the prepared BNT sample exhibits excellent dielectric properties over a wide temperature range, making it well-suited for a variety of applications.