Effect of thermal annealing on scintillation properties of Ce:Gd2Y1Ga2.7Al2.3O12 under different atmosphere

Cerium-doped 1% Ce:Gd 2 Y 1 Ga 2.7 Al 2.3 O 12 (GYGAG) single crystal samples grown via Czochralski method were annealed under air, O 2 and N 2 atmospheres from 350 to 1400 °C. The X-ray excited luminescence spectra, energy spectra and UV as well as thermally stimulated luminescence (TSL) spectra were performed comparatively on “as-grown” and thermally annealed samples. It was found that the luminescence efficiency after annealing in air and O 2 was significantly enhanced compared to the non-annealed samples and this phenomenon was suggested to be caused by the existence of some oxygen vacancies in the Ce:GYGAG crystals. And the oxygen vacancies in the as-grown GYGAG crystals can be effectively eliminated by means of annealing in O 2 containing atmosphere without changing the luminescence mechanism. From the TSL curves before and after annealing, three traps within 77–650 K were found to be related to oxygen vacancies.