Wet chemical synthesis of Eu2+ activated fluoro-elpasolite phosphors

A simple precipitation synthesis of fluoro-elpasolites is reported for the first time. X-ray diffraction results show phase formation for K2NaAlF6 and K2LiAlF6 precipitated from aqueous solutions. Intense Eu2+ emission in both the hosts is also reported for the first time. K2NaAlF6 exhibits both line and band emissions which are attributed to Eu2+ at K+ and Na+ sites, respectively. Only line emission is observed for K2LiAlF6. The emission is very strong, intensity being comparable to that of a commercial UV lamp phosphor. The photoluminescence spectra are explained on the basis of the known energy level scheme for Eu2+. It is suggested that fluoro elpasolite phosphors obtained by the new route can be useful for making further studies on these phosphors. (C) 2014 Elsevier B. V. All rights reserved.