Synthesis Of KMF₃（M=MN, Zn, Mg） By Molten Salt Method And Its Luminescence Property

Complex fluorides AMF₃, with A and M being respected by alkali metal andalkaline earth or transition metal, respectively, have drawn more and more attentionsfor their excellent properties, such as antiferromagnetism, magnetic, and opticalbehaviors.It is much severe to synthesis such compounds as for the corrosive nature of thefluorides. And this situation has limited the application of these materials. So far, avariety of synthesis routes have been studied to obtain AMF₃microcrystals,including conversional solid-state methods, hydrothermal, solvothermal techniques,micro emulsion, microwave initiated hydrothermal and solid-state methods. Butthese processes still have several disadvantages to overcome. Therefore, a simplerprocedure to synthesize the AMF₃is needed.Take all these into consideration, we use the Molten Salt Method （MSS） as afacile way to obtain KMF₃（M=Mg, Mn, Zn） microcrystal with high purity and goodcrystallinity. The reaction involves shorter holding time, lower reaction temperatureand mild reaction condition without any surfactant. It should be mentioned that theNH₄HF2flux was used as both react reagent and the fluxing agent to simplify theprocess and increase the purity. The effects of the reaction temperature, and holdingtime on the morphology of the products were also investigated.In addition, we obtain the KMgF₃:Eu microcrystals with good luminescentproperty by the same method. The sample got tunable emission through the change of the excited wavelengths, which was caused by the coexist of Eu³⁺and Eu²⁺. Andthese two color center corresponding to the red and blue emission. It is mentionablethat the KMgF₃sample synthesized by MSS method got broad emission at about430nm. And all the luminescent factor made the KMgF₃:Eu sample almost fullspectrum emission. Therefore, we may estimate the white emission of theKMgF₃:Eu microcrystals.