The pulsed cathodoluminescence spectra of "pure" crystals

Crystals Y LiF4 doped with rare-earth ions are promising scintillation materials with a broad spectrum of applications. Despite the fact that there is a lot of research about Y LiF4 crystals, information about the mechanisms of luminescence is not clear and incomplete. The pulsed cathodoluminescence of "pure" Y LiF4 crystals is studied in this paper. The spectra of PCL in the temperature range from 15 to 300 K are presented. The luminescence in the region 2 - 3.8 eV is due, probably, to the glow of the impurities that uncontrollably entered the crystal. The basis for this conclusion is the complex character of the spectrum in this region, its dependence on the history of the crystal, the presence in the spectrum of narrow lines characteristic of ions of rare earths - the most probable impurities in the Y LiF4 crystal.