Abstract
Barium titanate ceramics synthesized employing the solid-state method were investigated for their optical properties and phase transition characteristics. X-ray diffraction method and Scanning electronic microscopy were used to reveal a typical perovskite structure. The average grain size of (Sb or Y) doped barium titanate ceramics falls considerably as the concentration of Sb2O3 or Y2O3 increases. XRD investigation revealed the creation of cubic crystal structure. The impact of (Sb, Y) concentration on structure, including the appearance of various tetragonal phases, grain size reduction, and microstructure development, was investigated. The cell parameters of the formed phases decrease from 4.05418 to 3.99385 and from 4.05418 to 3.98605 as the doping rate increases Ba1-x SbxTiO3 and Ba1-xYxTiO3 ceramics respectively,where (x = 0.00,x = 0.05, x = 0.1, x = 0.15 and x = 0.20).Crystallites sizes of Sb-doped BaTiO3 crystals changes from 34.59 to 40.47 nm when dopant concentration is changed from 0.05 to 0.20. For Y doped BaTiO3 crystallite change in size from 28.92 to 29.10 nm. Additionally, assessed were the absorption coefficient (alpha), extinction coefficient (k), and refractive index (n). When the concentration of Sb3+ or Y3+ ions is increased from 0.05 to 20%, the values of the energy bandgaps for Ba1-x SbxTiO3 and Ba1-xYxTiO3 increase from 3.11 to 3.17 eV and 3.07-3.14 eV, respectively. It is found that the refractive index(n) rises as wavelength rises. It has been shown that the absorption coefficient (alpha) increases when photon energy increases. It is found that the extinction coefficient (k) decreases with wavelength. The extinction coefficient (k) and the absorption coefficient (alpha) are both observed to decrease with increasing concentration for all compositions.