Influence of Yb3+ content on microstructure and fluorescence of oxyfluoride glass ceramics containing LaF3 nano-crystals

The influence of Yb³⁺ content on structural evolution and fluorescence properties of oxyfluoride glass ceramics containing LaF₃ nano-crystals were systematically investigated. Differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) experiments indicated that Yb³⁺ ions acted as nucleating agent to facilitate LaF₃ crystallization. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) results verified the incorporation of Yb³⁺ into LaF₃ nano-crystal lattice. The absorption, emission spectra and fluorescence decays were measured. The infrared emission intensity of ⁴F_5/2 → ⁴F_7/2 transition under 980 nm excitation enhanced, while the measured lifetime reduced due to the increase of non-radiative transition probability, with the increase of Yb³⁺ content in glass ceramic. However, when Yb³⁺ doping reached 4.0 mol% the concentration quenching effect appeared.