Auger-free luminescence characteristics of Cs(Ca[formula omitted]Mgx)Cl3.

Fast scintillation materials based on ternary halide mixed crystals, Cs(Ca 1−x Mg x)Cl 3 , were synthesized. The luminescence at the defects or impurity sites within the band-gap excitation were observed. Upon X-ray excitation, bands corresponding to the intrinsic Auger-free luminescence (AFL) for CsCaCl 3 and CsMgCl 3 were observed, and the wavelength of the mixed crystals bands was similar to that of CsCaCl 3. Cs(Ca 1−x Mg x)Cl 3 exhibited a short decay time, which is typical for AFL in CsCl-based compounds, and CsMgCl 3 exhibited the shortest decay time of 1.1 ns and the smallest proportion of the first component (65%). On the other hand, CsCaCl 3 exhibited the longest decay time constant of 2.0 ns and the largest proportion of the first component (92%). The light yields of the fast components for CsCaCl 3 were larger than that of BaF 2 , whereas the light yields of the mixed crystals were lower than those of CsCaCl 3 and CsMgCl 3. The proportion of Cs/Mg in the mixed crystals was expected to affect the decay time constants and light yields, but changes in these properties did not vary much with Cs/Mg ratio. • Auger-free luminescence band was clearly observed under X-ray excitation for Cs(Ca 1−x Mg x)Cl 3. • Cs(Ca 1−x Mg x)Cl 3 exhibited short scintillation decay time constants of less than 2.0 ns. • The fast component light yields of CsCaCl 3 was larger than that of BaF 2 [ABSTRACT FROM AUTHOR]