Eu and Rb co-doped LiCaAlF6 scintillators for neutron detection

• Eu and Rb co-doped LiCaAlF6 crystals were grown by the micro-pulling down method.
• Transmittance, photoluminescence and radioluminescence spectra were measured.
• The light yields and scintillation decays were evaluated under 252Cf neutron irradiation.

Eu and Rb co-doped LiCaAlF6 (LiCAF) single crystals with different dopant concentrations were grown by the micro-pulling-down method for neutron detection. Their transmittance spectra showed strong absorption bands at 200–220 and 290–350 nm, and under 241Am alpha-ray excitation, their radioluminescence spectra exhibited an intense emission peak at 373 nm that was attributed to the Eu2+ 5d–4f transition. These results were consistent with those for the Rb-free Eu:LiCAF. The highest light yield among the grown crystals was 36,000 ph/n, which was 20% greater than that of the Rb-free crystal. In addition, the neutron-excited scintillation decay times were 650–750 ns slower than that of the Rb-free Eu:LiCAF.