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

Nano complex fluorides KAlF₄, NH₄AlF₄, Li₃AlF₆, Na₃AlF₆ were synthesized byreflux method and solvent-thermal method。The influence of different synthesisconditions such as reactants, ratio of reactants, reaction time and the kind of solventswere investigated in the paper. The structure, size and oxygen content of samples wereanalysized by means of X-ray powder diffraction, TEM and X-ray photoelectronspectrometry technology. It is found that reflux and solvent-thermal method cansynthsize complex fluorides with single-phase structure. The resluts showed that thesize of particles were smaller than 100 nm which belonged to namoparticle. Using Xrayphotoelectron spectrometry, it is confirmed that the samples does not contain theoxyfluoride and that the superficial oxygen content is low. Compared with solventthermalmethod, the reflux method has many advantages such as simple technology,mild conditions, fast phase-transformation rate and so on. The method can be usedfully in the future.KAlF₄, NH₄AlF₄, Li₃AlF₆, Na₃AlF₆, KAlF₄:Ce³⁺, NH₄MgAlF₆:Ce³⁺ andKFeF₃:Ce³⁺ had been synthesized with refluent glycol extraction method. The resultsXRD indicate that the value for the sample is similar to the data standard of cardand no impure peaks appear. This shows that the crystal structure don't changesignificantly by doping a small amount of Ce³⁺ ions. The product is single phase. Inthe emission of KAlF₄:Ce³⁺ powders, there is one sharp line emission located at 326nm, which is arisen from 5d-4f transition of Ce³⁺ in KAlF₄ lattice. In the emissionspectrum of NH₄MgAlF₆:Ce³⁺, there is one broad range of 300-400 nm with amaximum center located 335 nm, and their absorption and emission characteristics arebroadband. The result shows that the complex fluorides KAlF₄:Ce³⁺andNH₄MgAlF₆:Ce³⁺ are superior substrate of fluorescent material.