Influence of Zr Doping on the Structural and Dielectric Characteristics of ZnSnO₃ Ceramics

Developing lead-free, eco-friendly dielectric materials is essential for the advancement of next-generation electronic and energy storage devices. Among these, perovskite-type oxides such as zinc stannate (ZnSnO₃) are particularly promising due to their high dielectric constant, wide bandgap, and flexible crystal structure. In this study, zirconium (Zr⁴⁺)-doped ZnSnO₃ ceramics with the general formula ZnSn₁₋ₓZrₓO₃ (x = 0.1–0.5) were synthesized using the chemical precipitation method to investigate the influence of Zr⁴⁺ substitution at the Sn⁴⁺ (B-site) position on the structural, optical, and dielectric properties. X-ray diffraction (XRD) confirmed the formation of a single-phase orthorhombic perovskite structure at all doping levels, with peak shifts indicating lattice distortion and unit cell modification due to Zr⁴⁺ incorporation. Fourier-transform infrared (FTIR) spectroscopy exhibited well-defined metal–oxygen bonds, supporting the structural stability and bonding environment of the perovskite framework. Ultraviolet–visible (UV–Vis) spectroscopy revealed shifts in absorption behavior, implying changes in the electronic structure and possible bandgap modulation. Dielectric analysis demonstrated a consistent and progressive increase in the dielectric constant with increasing Zr content, attributed to enhanced ionic polarization, lattice distortion, and subtle structural modifications. These findings underscore the suitability of Zr-doped ZnSnO₃ ceramics as versatile, lead-free dielectric materials with strong potential for use in advanced electronic systems and sustainable technologies.