Study On Synthesis And Spectral Properties Of Nano Complex Fluorides Doped With Ce³⁺

Complex fluorides K₂AlF₅，CaAlF₅，SrAlF₅，BaAlF₅，Li₃AlF₆，Na₃AlF₆，K₃AlF₆and Na₃FeF₆were synthesized by reflux method using ethylene glycol asreaction solvent. The different reaction conditions such as the kind and ratio ofreactants, reaction time and reaction temperature were investigated. The samples weredetected by means of X-ray powder diffraction（XRD）, transmission electronmicroscopey（TEM） and X-ray photoelectron spectrometry（XPS）. The results showedthat complex fluorides with single-phase structure can be synthsized by reflux method.The average diameter of particles calculated by Debye-Scherrer Forlula were allsmaller than100nm which belonged to namoparticle. It is confirmed that onlychemi-adsorption oxygen existed on the surface of samples and the content of surfaceoxygen is low. The reflux method has many advantages such as simple technology,mild conditions, short reaction time, non-corroding equipment, need not burning, fastphase-transformation rate, easier to industrialized production, low conten of surfaceoxygen. Hence, the reflux method has broad prospect of development and application.Complex fluorides BaAlF₅：Ce³⁺，K₂AlF₅：Ce³⁺and K₃AlF₆：Ce³⁺weresynthesized by reflux method using ethylene glycol as reaction solvent. The sampleswere detected by means of X-ray powder diffraction（XRD） and fluorescencespectrometer. The XRD spectrum indicated that the main diffration peaks and relativeintensity of samples were consistent with the standard cards, the peaks were clear,distribute uniformly and no other impurity peaks, so the products were single phase. Itshows that the crystal structure don’t change significantly by doping a small amountof Ce³⁺ions. It was found by fluorescence spectroscopy analysis that the excitationpeaks of BaAlF₅：Ce³⁺，K₂AlF₅：Ce³⁺and K₃AlF₆：Ce³⁺were all between280and300nm, and the maximum peak was located290nm,284.6nm and288nm respectively.The emission spectrum consists of one broad range of475-535nm with a maximumcenter located503.2nm,497.6nm and508.4nm, which is arise from5d-4f transitionof Ce³⁺. The absorption and emission characteristics were broadband. The resultsshowed that the complex fluorides BaAlF₅：Ce³⁺，K₂AlF₅：Ce³⁺and K₃AlF₆：Ce³⁺areall superior substrate of fluorescent material.