Luminescence and scintillation properties of Ce3+-activated Cs2NaGdCl6, Cs3GdCl6, Cs2NaGdBr6 and Cs3GdBr6

We report on the structure, scintillation and luminescence properties of Cs2BGdX6:Ce (where B=Na, Cs; X=Cl, Br). Single crystals were obtained for four different compounds with both cubic and monoclinic structures. γ-ray spectroscopy measurements revealed light yields of 27,000 ph/MeV, 24,500 ph/MeV, 48,000 ph/MeV and 47,000 ph/MeV and energy resolutions of 4.0%, 4.5%, 3.3%, and 4.0% for Cs2NaGdCl6:Ce, Cs3GdCl6:Ce, Cs2NaGdBr6:Ce and Cs3GdBr6:Ce, respectively. X-ray emission and optical emission measurements of the samples exhibited both the characteristic Ce3+ 5d-4f emission and the Gd3+ 4f-4f emission. The optimal concentration of Ce3+ for these compounds was also determined from X-ray excited luminescence decay measurements of polycrystalline forms of these materials.