Study of luminescence in Eu2+ activated LiF-CaF2 & NaF-CaF2 eutectic systems

Since, perovskites like LiCaF3 and NaCaF3 do not exists, there lies a eutectic point in LiF-CaF2 system at 762 °C which is considerably lower than their respective melting points of LiF and CaF2 for 77/23% molar ratios. Similarly, for NaF-CaF2 system, it exists at 818 °C for 67/33%. Preparing phosphors at such low temperatures via solid state diffusion is obviously advantageous over the conventional ways of syntheses. Hence, we are successful in obtaining Eu2+ and Ho3+ codoped CaF2 phosphors through this new technique. Though the presence of LiF in LiF-CaF2 system hindered luminescence efficiency in our samples but as prepared samples showed photoluminescence immediately after melting at eutectic temperature. To overcome reduced luminescence intensity disadvantage, we replaced LiF by NaF and investigated NaF-CaF2 system as NaF is water soluble. Results obtained are thus discussed here.