Growth of GSAG:Ce scintillation crystals by the Bridgman method: influence of Ce concentration and codoping
Résumé
Single crystals of Ce-doped gadolinium scandium aluminum garnet (Gd3Sc2Al3O12; GSAG) with Ca2+, Mg2+ and Li+ co-dopants were grown by the Bridgman method. Regardless of melt composition, crystals tend to grow close to the congruent composition. Introduction of Ca2+ or Mg2+, as in other Ce-doped garnets, leads to an increase of absorption below 350 nm, which may indicate formation of Ce4+ states, while no effect is seen with Li+ co-doping. High Ce concentration and co-doping accelerate the scintillation rise and decay times; the codopants strongly significantly reduce the afterglow.
Illustrative decays highlight the range of rise (15 to 45 ns) and decay times (27 to 76 ns).