Luminescence properties of BaMO4:Eu3+(M: Mo or W) phosphors derived from co-precipitation reaction

Luminescent BaMO4:xmol%Eu3+ materials (M: Mo or W, and x: 0, 2, 4, 6, 8, and 10 mol%) were successfully obtained by a coprecipitation method at room temperature without additional thermal treatment, leading to highly crystalline materials with reduced reaction times and low manufacturing cost. Structural analyses by powder X-ray diffraction and vibrational Raman techniques of the [WO4]2-and [MoO4]2-groups confirm a characteristic scheelite-type structure. The results indicate an average crystallite size at around 30 nm, and a highly pure phase has been supported by Rietveld refinement. SEM-EDS data of BaMO4:xmol%Eu3+ materials identified polycrystalline particles with bipyramidal-like morphology and homogeneous europium ion distribution. Additionally, the band gap energy (Eg) of barium molybdate and tungstate materials were calculated from reflectance data by the single-constant Kubelka-Munk function. Furthermore, the emission intensity, lifetime, and intrinsic emission quantum yield (+ Eu + Q3) of the materials have been deEu3 termined and discussed. The luminescent properties of these materials are significantly influenced by the LMCT excitation bands (O2--> Mo6+, W6+, and Eu3+) as well as their intense red emission bands assigned to Eu3+ transitions. The experimental intensity parameter values Omega 2 and Omega 4 were evaluated from the emission spectra, using the magnetic dipole 5D0 -> 7F1 transition as the standard reference. It was observed that the Omega 2 values are much higher than the Omega 4 values. This result is related to the fact that the 5D0 -> 7F2 transition presents a much higher intensity than 5D0 -> 7F1 one suggesting a low local symmetry around the Eu3+ ion, which might be due to angular distortions in the local coordination geometry. The high + 3values + QEuEu3 (60-79%) indicated an overall high emission intensity for the prepared phosphors. These are special photonic features of the Eu3+-doped molybdate and tungstate, suggesting they could be suitable for luminescent materials applications.(c) 2022 Elsevier B.V. All rights reserved.