Effect of Ca 2+ and Zr 4+ co-doping on the optical properties of Gd 3Al 2Ga 3O 12: Ce single crystals

Abstract

Scintillation materials capable of transforming absorbed high-energy particles into visible radiation photons find multiple applications including advanced medical visualization methods. Gd3Al2Ga3O12 : Ce is a promising oxygen-containing sсintillator for fabrication of detecting crystals of positron emission tomographs due to its unique properties, e.g. high density, high light yield, radiation hardness etc. However its kinetic parameters currently restrict its use in this field. Attempts at improving the luminescence rise and decay time kinetics by introducing additional impurities have become a top priority task for many researchers. Analyzing literary data one can conclude that the optical parameters of co-doped crystals have been studied insufficiently or have not been studied at all. We have studied Ca2+ and Zr4+ co-doped Gd3Al2Ga3O12 : Ce single crystals by optical spectroscopy in the 200–2200 nm. We have taken the optical transmittance, absorption and reflection spectra and measured the refractive indices. Dispersion curves have been obtained by approximation of experimental refractive indices using the Brewster method and the Cauchy equation. Material constants of these equations have been estimated for each of the co-doped crystals.

The First Application of a Gd3Al2Ga3O12:Ce Single-Crystal Scintillator to Neutron Radiography

“…The decay time of emitted light is too short, and considering the X-ray energy resolution is not necessary. Therefore, material design to increase the light yield by neutron irradiation will make the GAGG a good neutron scintillator, for example, by selecting doping elements and optimizing their amounts to generate suitable emission centers similar to studies conducted for X-ray use [26][27][28], or adjusting matrix crystal composition to exhibit an appropriate band gap and high enough Gd concentration. Owing to increase in the light yield, the GAGG will be a good alternative candidate to Gadox enriched with 157 Gd isotope.…”

Novel Phenomenon of Scintillation Performances with the Component Variation in the Mg Co-/Nondoped GAGG:Ce Crystal

“…Cerium (Ce)-doped rare-earth garnet crystals are promising candidates for scintillation applications due to their high light yield, excellent energy resolution, and high density, such as the Gd 3 Al 2 Ga 3 O 12 :Ce (GAGG:Ce) crystal, which shows 58,000 ph./MeV of light yield, 4.9%@662 keV of energy resolution, and 6.63 g/cm 3 of density. , Moreover, GAGG:Ce also has a high effective atomic number, radiation resistance, non-self-radiating, and nonhygroscopicity properties. , Therefore, GAGG:Ce has great potential for the TOF technology of nuclear medicine imaging devices and γ detection applications . In the GAGG:Ce scintillator, although the introduction of low-valent cations such as Mg 2+ , − Ca 2+ , ,, and Li + − can significantly accelerate the scintillation decay, it also deteriorates the light yield. However, the light yield and scintillation decay can be simultaneously improved by codoping with low concentrations of Ca 2+ in the LSO:Ce crystal .…”