Synthesis and optical characterization of Eu³⁺-doped CaTiO₃ embedded into a–SiO₂ sonogel hosting

Ceramic powders of Ca_1-xEu_xTiO₃ (x = 0.0, 0.01, 0.02, 0.03 and 0.04) were synthesized by the polymeric complex method and annealed at 1000 °C for 1 h. These phosphors were embedded into a–SiO₂ sonogel hosting at different dopant ratios to obtain luminescent Ca_1-xEu_xTiO₃:SiO₂ glasses. The powders and glasses were characterized by X-ray diffraction, scanning electron microscopy, absorption, and photoluminescence spectroscopy. The obtained powders have an orthorhombic crystal structure. The luminescence spectra from all samples show the characteristic red emission peaks from the Eu³⁺ ion associated with inter-electronic energy level transitions. However, the excitation spectra in these nanophosphors are dominated by the ⁷F₀–⁵L₆ transition (395 nm), as opposed to the dominant charge-transfer related band at~260 nm commonly reported.