Influence of Ca2+ and Zr4+ codoping on the optical characteristics of Gd3Al2Ga3O12:Ce single-crystal

Scintillation materials that can convert absorbed high-energy particles into photons of visible radiation find many applications, in particular in modern methods of medical imaging. Gd3Al2Ga3O12 : Ce is promising single crystal for use as a detecting crystal element of the positron emission tomographs due to its unique properties: high density, high light output, radiation hardness, etc. However, its scintillation kinetics currently limit the use of this crystal. Changing of these kinetics by codoping becomes a priority task, which is considered in many papers. The literature data analysis showed that the optical characteristics of such codoped crystals were not well enough studied or were not investigated at all. In this regard, the spectral dependences of transmission, absorption and reflection are measured using optical spectroscopy for Gd3Al2Ga3O12:Ce, Gd3Al2Ga3O12 : Ce,Ca and Gd3Al2Ga3O12 : Ce,Zr. Dispersion dependences of refractive in dices are obtained by approximating the refractive indices measured using the Brewster method. The approximation was carried out using the Cauchy equation. The material constants of this equation are estimated.