Study On Nd-doped Transparent Oxyfluoride Glass-ceramic Laser Material

A series of novel Nd³⁺-doped transparent oxyfluoride glass ceramics containing CaF₂ were prepared through controlled crystallization of melt-quenched glass.X-ray diffraction (XRD) analysis and field emission ground environmental scanning electron microscopy (FEG-ESEM) observation revealed the precipitation of CaF₂ crystallites with about 15 nm in size among the glass matrix after the best heat-treatment system. Non-isothermal investigation on CaF₂ crystallization kinetics showed that the apparent activation energy Ea and Avrami exponent n of Si-Al-Ca-Na-O-F system and Si-Al-Li-Ca-O-F system are about 308.7kJ/mol, 1.095 and 280.9kJ/mol, 1.215 respectively, indicating the crystallization a diffusion controlled growth process with zero nucleation rate. The optical transmittance was about 78-87% in the visible region and 84-93% in the near-infrared region. Fluorescence measurements exhibited a stronger emission especially at 1060nm in the glass ceramics than in the precursor glass, together with the excited emission section value(σ) 10% larger than the precursor glass, due to the incorporation of Nd³⁺ into CaF₂ during crystallization, proved the material to be ideal laser material.