Synthesis Of Rare Earths Doped Fluorides And Study On Emission Band FWHM Broadening

BaF₂:Ce³⁺ nanorods and MgF₂:Ce³⁺ tetragonal phases were prepared in CTAB/ cyclohexane/n-pentanol/water quaternary microemulsion at 160℃for 12h and at 140℃for 12h, respectively. The X-ray diffraction (XRD) patterns were indexed to pure phases. Environment scanning electron microscope (ESEM) was employed for the characterization of morphology and size of the obtained products. The results showed that the diameter of BaF₂:Ce³⁺ nanoparticles is 50¹00nm and the length is 800nm⁵μm. the molar ratio of water to the surfactant CTAB,reactant temperature,reactant time,ageing time and the concentration of CTAB all could affect the morphology and size of the products. The analysis showed that the sizes of BaF₂:Ce³⁺ nanoparticles affected on emission spectra.KMgF₃:Ce³⁺ particles were prepared at 140℃for 6 days with synthesized MgF₂:Ce³⁺ as precursor. The X-ray diffraction (XRD) patterns were indexed to a pure KMgF₃ cubic phase. Environment scanning electron microscope(ESEM) showed the shape is cubic, the length of side is about 1μm .The emission of prepared KMgF₃:Ce³⁺particles under hydrothermal peaked at 343nm, The excitation band was observed at 253nm, red shifted about 13nm and the FWHM bandwidth broadens 40nm compared with KMgF₃:Ce³⁺ nanoparticles under microemulsion conditions. The Ce³⁺ luminescence intensity increases by 3 times from MgF₂:Ce³⁺ tetragonal phase to KMgF₃:Ce³⁺ cubic phase.