Synthesis of Eu-doped K_0.5Na_0.5NbO₃ ceramics and their luminescent and dielectric properties

K_0.5Na_0.5NbO₃:xEu sol–gel powders and bulk samples were synthesized by means of a modified sol–gel method. Two types of samples were obtained via sintering at two temperatures. X-ray diffraction revealed the presence of the perovskite phase in materials obtained at both temperatures. Eu³⁺ emission and excitation studies were conducted to determine its luminescence response. For K_0.5Na_0.5NbO₃:xEu sinters, the excitation spectra included narrow peaks in the VIS range due to the ⁵D₀–⁷F₁ and ⁵D₀–⁷F₂ relaxation processes. These transitions were indicative of the presence of Eu³⁺ at sites of low symmetry. Dielectric studies indicated that Eu₂O₃ affected the observed phase transitions. The influence of sintering temperature on structure and physicochemical properties was discussed.