Growth and Scintillation Properties of Ce: Li(Ca,Ba)AlF $_{{6}}$ Scintillator Crystals

Ba co-doped Ce:LiCaAlF₆ [Ce:Li(Ca,Ba)AlF₆] and LiCaAlF₆ [Li(Ca,Ba)AlF₆] crystals with various Ba concentrations were grown and their structures, optical and scintillation properties were investigated. As-grown Ce2%Ba1% and Ce2%Ba2%:Li(Ca,Ba)AlF₆ crystals were high transparency in all parts while an end part of as-grown Ce2%Ba5%:Li(Ca,Ba)AlF₆ crystal and all parts of as-grown Ba5%:Li(Ca,Ba)AlF₆ crystal included milky parts which decreased transmittance. Ce:Li(Ca,Ba)AlF₆ crystals indicated the emission peaks at 288 and 308 nm from which was attributable to the 5d-4f transition of Ce³⁺ ion in the radioluminescence spectra under α-ray irradiation. In the case of Ce1%Ba2%:Li(Ca,Ba)AlF₆ crystal, light yield under thermal neutron irradiation were improved. Decay times of Ce:Ce:Li(Ca,Ba)AlF₆ under thermal neutron irradiation systematically increased with an increase of Ba concentration.