Synthesis and Structural Probing of Eu ³⁺ Doped BaYF ₅ Nano‐Crystals in Transparent Oxyfluoride Glass‐Ceramics

Abstract

Transparent oxyfluoride glass‐ceramics containing Eu : BaYF 5 nano‐crystals in the newly developed SiO 2 – K 2 CO 3 – BaF 2 – YF 3 – Sb 2 O 3 glass system are synthesized by melt quenching method followed by optimized ceramization process. The X ‐ray diffraction, transmission electron microscopy, and field emission scanning electron microscopy confirmed the precipitation of tetragonal BaYF 5 nano‐crystals in glass matrix. The coexistence of Eu 2+ and Eu 3+ ions in both glass and glass‐ceramics are ascertained from their emission and excitation spectra. The in situ formation of divalent europium ( Eu 2+ ) along with Eu 3+ during high temperature synthesis under ambient atmosphere is explained through optical basicity model. The Eu 3+ emission from upper excitation states ( 5 D 3−1 ) and reduced asymmetry ratio ( R = I ED / I MD ) in glass‐ceramics have established the dopant ion incorporation into fluoride nano‐crystalline environment. The observed luminescence properties of Eu : BaYF 5 are compared with that of Eu : BaYF 5 nanocrystals containing transparent glass‐ceramics and their marked differences are discussed.