RESUMO
Borogermanate glasses show promise as scintillators due to their ability to incorporate high levels of heavy metal oxides without excessive loss of luminescent output intensity. Heavy metal oxide scintillating glasses of 50GeO2-25B2O3-(25-x)La2O3/Gd2O3-xTb2O3 (x=1,2,3,4) with the same stoichiometric composition of crystalline Tb doped LaBGeO5/GdBGeO5 were synthesized via the melt-quench method. Three times of higher light output under gamma ray excitation was observed from Tb doped GdBGeO5 based glass compared to LaBGeO5 glass due to efficient energy transfer between Gd-Tb pairs and higher luminescence efficiency in the GdBGeO5 glasses. The potential to form LaBGeO5/GdBGeO5 glass ceramic scintillators was also discussed and preliminarily investigated.
RESUMO
Transparent glass ceramics with embedded light-emitting nanocrystals show great potential as low-cost nanocomposite scintillators in comparison to single crystal and transparent ceramic scintillators. In this study, cubic structure BaGdF5:Tb nanocrystals embedded in an aluminosilicate glass matrix are reported for potential high performance MeV imaging applications. Scintillator samples with systematically varied compositions were prepared by a simple conventional melt-quenching method followed by annealing. Optical, structural and scintillation properties were characterized to guide the design and optimization of selected material systems, aiming at the development of a system with higher crystal volume and larger crystal size for improved luminosity. It is observed that enhanced scintillation performance was achieved by tuning the glass matrix composition and using GdF3 in the raw materials, which served as a nucleation agent. A 26% improvement in light output was observed from a BaGdF5:Tb glass ceramic with addition of GdF3.
