Microstructure and luminescence of transparent glass ceramic containing Er3+:BaF2 nano-crystals

Transparent BaF2–SiO2 glass ceramics doped with different content of Er3+ were prepared by sol–gel method. The microstructural evolution of the samples was studied with X-ray diffraction (XRD), transmission electron microscope (TEM), absorption and infrared spectra (IR). BaF2 nano-crystals with 2–15 nm in size, depending on the crystallization temperature, distributed homogeneously among the amorphous silica matrix. The BaF2 lattice parameters decreased with the increasing of Er3+ doping, indicating the incorporation of Er3+ into nano-crystals, which was further confirmed by energy dispersive X-ray spectroscopy (EDS) and absorption spectra analysis. The upconversion emissions of Er3+ emerged under the excitation at 980 nm for glass ceramic heat-treated at 800 °C.