| The complex fluoride ABF3 with perovskite structures were carried out bysolvent-thermal method and the reflux method. We confirmed the samples are singlephaseby means of X-ray powder diffraction, and the samples are purer compared withthat by high temperature solid-state method. Using XRD and TEM to analyse thecrystal structure, we found the granula size of samples is smaller than 100nm and itbelongs to nanocrystalline. Using X-ray photoelectron spectrometry, it is confirmedthat the samples does not contain the oxyfluoride and that the superficial oxygencontent is low; The infrared analysis indicated that the product does not contain theintramolecular crystal water.Research on synthetic condition, we found that factors of filling, reactant ratio,reaction temperature, reaction time and the kind of solvents are important factorsinfluencing reaction. The best ratio of filling is 75%-80%. Raising the temperatureand prolonging the reaction time is important to form a good crystal. The appropiatereactant ratio and reaction solvent have the material effect on the product formation.Through the analysis of the reaction conductivity, the product's XRD spectrum,and the product's IR spectrum of different time, we infer reflux method reactionmechanism initially. During heating process, Ni(NO3)2 and ethanediol forms metalcomplexes gradually. Along with the extension of reaction time, the complexesdecompose gradually, and finally produce KNiF3 precipitation with K+ and the F- ion.The formation speed and quantity of NO3- ion are roughly equal to the depletionspeed and quantity of K+ and F-ion in the formation of KNiF3 , so changes in theconductivity is not obvious.In addition, this article has carried on the desk study to the synthetic method ofmetallic oxysulfideme. The sample was carried out by solvent-thermal method andwas confirmed as LaCrSxOy by XPS and XRD. It has better photo-catalytic activityby the photocatalytic degradation experiments.
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