Perovskite oxide material of Ba 1-x Ca x TiO 3 (where x = 0.0, 0.1, 0.2, and 0.3) was prepared via the conventional hightemperature solid-state double-sintering ceramic technique. Replacing Ba 2+ ions with Ca 2+ at the A-site was found to enhance the temperature stability of the phase while simultaneously reducing the degree of tetragonality. The X-ray diffraction (XRD) patterns confirmed a single-phase tetragonal perovskite structure with P4mm symmetry for x =0.0, X = 0.1, and 0.2, whereas x = 0.3 displayed a mixed tetragonal–orthorhombic structure, with crystallite sizes ranging from 28.947 nm to 20.841 nm. The surface morphology was examined using Scanning Electron Microscopy (SEM), revealing predominantly spherical grains with an average grain size of the range 0.468 to 0.985 μm and EDX analysis verified the composition of Ba, Ca, Ti, and O. The dielectric properties of all ceramics were investigated in the temperature range of 25 °C to 150 °C, the composition x = 0.2 shows the best functional performance: it combines the highest dielectric constant (ε r . = 6512.45) and low loss factor (tan δ = 0.01634) with enhance thermal stability and a favorable structural tolerance factor. This composition presents the optimal balance between ferroelectric tetragonality and A-site modification, and incorporation of Ca 2+ ions enhanced the electrical response of the ceramics, where conductivity showed a positive correlation with temperature, making them suitable for energy-storage capacitor applications.
Salunkhe et al. (Thu,) studied this question.