Study of the structural, optical and dielectric properties of the Ba _0.95 Sm _0.034 Ti _{(1− <i>x</i> )} Zr _<i>x</i> O ₃ solid solution

The solid solution Ba_0.95Sm_0.034Ti_1-<i>x</i> Zr _<i>x</i> O₃, with <i>x</i> = 0.01, 0.05, and 0.10, was synthesized <i>via</i> the solid-state reaction method at 1200 °C for 6 h. The obtained powders were first characterized by X-ray diffraction (XRD) to confirm the formation of the expected phase. All samples were found to exhibit a tetragonal structure with space group <i>P</i>4<i>mm</i>, as determined by Rietveld refinement of the XRD data. Increasing the zirconium content led to an expansion of the unit cell volume and a distortion of the [Ti/ZrO₆] octahedra. Scanning electron microscopy (SEM) images of pellets sintered at 1300 °C for 6 h showed a denser microstructure with larger grains in Zr-rich ceramics. A significant modification of the optical bandgap energy was observed with increasing Zr content. Dielectric measurements showed that the Curie temperature gradually decreases with increasing zirconium content. The electrical properties were influenced by the contributions of grains and grain boundaries. The total electrical resistance (<i>R</i> _tot = <i>R</i> _g + <i>R</i> _gb) increased with the zirconium content. The analysis of the complex electrical modulus confirmed a non-Debye behavior for all the ceramics studied in this work.