Effect of Europium Ion Concentrations on the Photoluminescence Emission of Nano-Crystalline BaTiO₃ Prepared by Sol–Gel Technique

Abstract

Nano-crystalline. ferroelectric Eu³⁺: BaTiO₃ powders and thin films have been prepared using (Ba(Ac)₂), and titanium butoxide (Ti(C₄H₉O)₄), as precursors. The thin films were prepared by spin coating using the sol–gel method. The evolution of the network bonds and the structural characterization of the prepared samples was studied by Fourier Transform Infrared Spectrometer (FTIR) and X-ray diffraction (XRD) techniques, respectively. The as-grown thin films and powders were found to be amorphous, and crystallized to the tetragonal phase after annealing at 750^∘C in air for 30 min. The crystallite size of the doped sample with 4% Eu³⁺ ions in the form of thin film and powder was found to be equal to = 21 and 32 nm, respectively.

The photoluminescence of nano-crystalline powders and thin films at 488 nm were reported. The luminescence spectra of ultra fine Eu³⁺: BaTiO₃ powders and thin films are dominated by the ⁵D₀ → ⁷F_j (j = 0−4) transitions, suggesting a strong distortion of the Eu³⁺ sites. The disorder contributes, together with the presence of numerous charge compensation mechanisms, to the strong inhomogeneous broadening of the ⁵D₀ → ⁷F_j luminescence band of the Eu³⁺.