Journal of Crystal Growth, Vol.507, 332-337, 2019
Growth and characterization of Cs2LiLaCl6:Ce single crystals
Cs2LiLaCl6:Ce (CLLC) is a promising scintillator material for dual gamma/neutron detection. The vertical Bridgman technique, with a LiCl-rich melt and high axial temperature gradient, was used to grow transparent CLLC crystals for the first time. The stoichiometric CLLC powder melted incongruently with a melting range of 343-442 degrees C. Additional LiCl suppressed the formation of Cs3LaCl6 second phase, which was identified in crystals grown from stoichiometric melts. CLLC was found to have a Stokes shift of about 1358 cm(-1) and a photoluminescence decay time of 34.6 ns. Direct electron-hole capture by Ce3+ ions and core-valence luminescence were the main contributors to the X-ray induced luminescence spectrum. A empty set9 x 8 mm(3) cylinder of the CLLC crystal with 0.5at% Ce had an energy resolution of 7.1% at 662 keV. The scintillation decay times of the CLLC crystal excited with 662 keV gammas were 79 ns and 1491 ns.
Keywords:Absorption spectra;Bridgman technique;Cs2LiLaCl6:Ce;Scintillator materials;Neutron detection