Ce3+ activated LaBr3-xIx: High-light-yield and fast-response mixed halide scintillators.

Here, we report the scintillation properties of LaBr_3-xI_x:5%Ce³⁺ with four different compositions of x, i.e., x=0.75, 1.5, 2, and 2.25. Radioluminescence spectra reveal a shift of the emission wavelength with the LaBr₃ to LaI₃ ratio. LaBr_1.5I_1.5:5%Ce³⁺ shows the highest scintillation light yield of 58 000 photons/MeV, whereas LaBr_0.75I_2.25:5%Ce³⁺ shows the fastest scintillation decay time of 12 ns under 662 keV γ-ray excitation. This decay time is faster than that of 16 ns in LaBr₃:Ce³⁺. The temperature dependence of radioluminescence spectra is presented. The structures and lattice parameters of the materials were determined from powder x-ray diffraction. [ABSTRACT FROM AUTHOR]