Synthesis, Characterization and Photophysical Properties of Eu3+ Doped in BaMoO4

In this work Ba 0.99 Eu 0.01 MoO 4 (BEMO) powders were prepared by the first time by the Complex Polymerization Method. The structural and optical properties of the BEMO powders were characterized by Fourier Transform Infra-Red (FTIR), X-ray Diffraction (XRD), Raman Spectra, High-Resolution Scanning Electron Microscopy (HR-SEM) and Photoluminescent Measurements. XRD show a crystalline scheelite-type phase after the heat treatment at temperatures greater than 400 °C. The ionic radius of Eu 3+ (0.109 nm) is lower than the Ba 2+ (0.149 nm) one. This difference is responsible for the decrease in the lattice parameters of the BEMO compared to the pure BaMoO 4 matrix. This little difference in the lattice parameters show that Eu 3+ is expected to occupy the Ba 2+ site at different temperatures, stayed the tetragonal (S 4 ) symmetry characteristic of scheelite-type crystalline structures of BaMoO 4 . The emission spectra of the samples, when excited at 394 nm, presented the 5 D 1 → 7 F 0, 1 and 2 and 5 D 0 → 7 F 0, 1, 2, 3 and 4 Eu 3+ transitions at 523, 533, 554, 578, 589, 614, 652 and 699 nm, respectively. The emission spectra of the powders heat-treated at 800 and 900 °C showed a marked increase in its intensities compared to the materials heat-treated from 400 to 700 °C. The decay times for the sample were evaluated and all of them presented the average value of 0.61 ms. Eu 3+ luminescence decay time follows one exponential curve indicating the presence of only one type of Eu 3+ symmetry site.