Crystal Growth and Scintillation Properties of Ce-Doped ${\rm K}_{2}{\rm NaLuF}_{6}$

Ce 0.1, 0.5, 1.0, and 2.0 mol%-doped K₂NaLuF₆ crystals with 2 mm in diameter and 30-50 mm in length were grown by micro-pulling-down method. The photoluminescence spectra under ultraviolet excitation showed intense emission ascribed to 5d-4f transitions of Ce³⁺ replacing Lu³⁺ isolated octahedral site. In the radioluminescenced spectra under alpha-ray irradiation, the emission band is due to the transition from the lowest 5d excited state of Ce³⁺ to ²F_5/2 ground state level is dominant. The light yields of Ce:K₂NaLuF₆ under 5.5-MeV alpha-ray excitation was estimated to be approximately 1.2 to 1.8% of those of BGO.