Luminescence and scintillation properties of TlMg(Cl1-xBrx)3 crystals

Herein, we report the luminescence and scintillation properties of various TlMg(Cl_1-xBr_x)₃ crystals prepared under vacuum via self-seeding solidification. The emission peak wavelengths of the X-ray-induced scintillation spectra for the TlMg(Cl_1-xBr_x)₃ crystals were similar to those of TlMgCl₃. Two exponential scintillation decay time components of 19 ns (7%) and 367 ns (93%) were observed. The decay times of TlMg(Cl_1-xBr_x)₃ were similar to those of TlMgCl₃. The light yield of TlMg(Cl_1-xBr_x)₃ (x = 0.0168, 59,000 photons/MeV) was higher than that of TlMgCl₃ (42,000 photons/MeV) and the light yield of TlMg(Cl_1-xBr_x)₃ peaked at 0.5–1.2 mol% and subsequently declined. This is likely due to the decreased trapping of the lattice defects as confirmed by the significantly lower thermoluminescence intensity of TlMg(Cl_1–xBr_x)₃ (x = 0.0168) than that of TlMgCl₃. These results indicated that the TlMg (Cl_1-xBr_x)₃ crystalline scintillators could be successfully improved via anion substitution.