Shaped single crystal growth and scintillation properties of Bi:Gd_3Ga_5O_(12)

摘要

Shaped single crystals of Bi:Gd_3Ga_5O_(12) (Bi = 0.102, 0.126 and 0.141%) were grown by the modified micro-pulling-down method. Strong evaporation of Bi during single crystal growth leading to lower concentration in the obtained crystals was detected. Measured optical absorption spectra show an absorption band round 290 nm ascribed to the lowest energy 6s~2 → 6s6p transition of Bi~(3+). In the radioluminescence spectra in the region of 440-560 nm an emission composed of two bands and depending on Bi concentration was found and completed by the decay kinetics measurements. Unsuitability of Bi-doping in the Gd_3Ga_5O_(12) host to get energy transfer from Gd~(3+) towards Bi~(3+) centers was concluded.