Structure, microstructure and charge dynamics in Sn⁴⁺modified Ba(Zn_1/3Sn_x/3 Nb_2-x/3)O₃ ceramics

Ternary Sn4+ doped Ba(Zn_1/3Sn_x/3Nb_2-x/3)O₃ (BZSN) ceramics with 0.00 ≤ x ≤ 0.15 were synthesized via the solid-state reaction method calcined at 1100 °C and sintered at 1200 °C. Structural, microstructural, dielectric, and electrical characteristics were systematically analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and impedance spectroscopy. XRD confirmed a single-phase cubic perovskite structure (Pm3m, JCPDS 89-3115), with diffraction peaks shifting to higher 2θ for Sn contents x ≥ 0.05, corresponds to a decrease in interplanar distance causes a contraction in the unit cell and remains stable for any further increase of Sn concentration. SEM images revealed dense microstructures and grain size reduction from 1.15 μm (x = 0) to 0.16 μm (x = 0.15) with increasing Sn4+ content. Dielectric measurements showed a decreasing relative permittivity from 1270 to 105 (for x = 0.0 and 0.15) with Sn4+ doping from room temperature to 500 °C at 1 kHz. The I-V characteristic of BZSN as a function of voltage with different elevated temperatures were ohmic at ≤ 350 °C but non-ohmic at 500 °C and enhanced the flow of current to (Formula presented) .