New luminescent systems based on fluoride crystals doped with rare earth ions

Results of recent investigation aimed at finding new efficient laser active materials and converters of VUV radiation into visible emission are summarised. Representatives of two families of compounds with general chemical formulae: K5Li2LnF10 (Ln3+ = Ce, La-Gd) and M3LnF6 (M+ = K+, Cs+, Rb+; Ln3+ = La-Yb) as well as a new compound Na2K2NdF7 have been synthesised by a solid state reaction and next obtained in a single crystal form by the Bridgman method. Crystal structures of compounds have been ascertained based on X-ray measurement on single crystal samples. Spectroscopic properties of crystals have been determined based on optical absorption spectra, emission spectra and luminescence decay curves recorded at temperatures between 4.2 and 300 K in the UV-VIS-NIR spectral region. Optical properties and material parameters relevant to application of the crystals will be presented and discussed.