Spectroscopic studies of Eu-Doped BaF₂ single-crystal

Spectroscopic studies of Eu-doped BaF₂ single crystals were carried out in view of novel possible applications in laser technology. Single-crystal X-ray diffraction confirmed that the Eu: BaF₂ single crystal process FCC crystal structure with Fm-3m space group. The vibrational mode of the Eu: BaF₂ crystal was observed at 245 cm⁻¹. Five absorption lines are observed at 398, 405, 415,462, and 471 nm, corresponding to the ⁷F₀ → ⁵L₆, ⁷F₁ → ⁵L₆, ⁷F₁ → ⁵D₃, ⁷F₀ → ⁵D₂, and ⁷F₁ → ⁵D₂ transitions, respectively. The ⁷F₀ → ⁵L₆ transition has a maximum absorbance and oscillator strength of ~ 2.03 × 10^–6. The fluorescence spectra showed four emission lines at 588, 618, 652, and 699 nm. These lines correspond to ⁵D₀ → ⁷F₁, ⁵D₀ → ⁷F₂, ⁵D₀ → ⁷F₃, and ⁵D₀ → ⁷F₄ transitions, respectively. Judd–Ofelt parameters were calculated from the fluorescence spectra using JOES software. Eu is localized at a highly symmetric site, as the JO intensity parameter Ω₂ (0.54 × 10⁻²⁰cm²) is less than Ω₄ (0.99 × 10^–20 cm²). The emission cross-section values, branching ratio, lifetime, and radiation transition probability have been computed using the JOES software. The ⁷D₀ → ⁷F₁ transition has a higher lifetime, branching ratio, and emission cross-section values.