Exploring the effects of zirconium doping on barium titanate ceramics: structural, electrical, and optical properties

Abstract

In this study, polycrystalline BaZr_xTi_1−xO₃ (x = 0.00, 0.05, 0.10, 0.15, and 0.20) ceramics were synthesized through a solid-state reaction technique. The effect of zirconium doping on the properties of barium titanate (BaTiO₃) was investigated by various characterization tools. The structural and morphological properties of the synthesized materials were studied by X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). The electrical properties of the Zr-doped BaTiO₃ (BZT) materials were examined by impedance spectroscopy and the optical properties were investigated using UV-Vis-NIR spectroscopy. The XRD analyses of the prepared BZT materials revealed a single-phase tetragonal structure. The inclusion of Zr⁴⁺ in the BT matrix did not significantly affect the Raman-active modes, suggesting that the tetragonal crystal structure was retained in the as-synthesized samples. FE-SEM analyses revealed that the grain size initially increased from 49.36 nm to 53.24 nm for x = 0.05 wt% and then decreased gradually for higher concentrations up to x = 0.15 wt% (26.99 nm). The dielectric constant, dielectric loss, conductivity, and quality factor determined from the impedance data demonstrated that Zr⁴⁺ addition significantly influenced the electrical properties of BT. The band gap energy, E_g, of the synthesized samples were found in the range of 3.19–3.37 eV, which was calculated from the diffuse reflection data. The experimental results suggest that the BZT ceramic materials are suitable for energy storage device applications.