Combinatorial Approach for the Discovery of New Scintillating Materials SBIR Phase I Final Report DOE/ER/84310

The combinatorial approach for the discovery of new scintillating materials has been investigated using the wet-chemical (sol-gel) synthesis methods. Known scintillating compounds Lu2SiO5 (LSO) and (LuAl)O3 (LAO) and solid solutions in the systems of Lu2O3-Y2O3--SiO2 (CeO2-doped) (LYSO) and Lu2O3 -Y2O3--Al2O3 (CeO2-doped) (LYAO) were synthesized from sol-gel precursors. Sol-gel precursors were formulated from alkoxides and nitrates and acetates of the cations. Sol-gel solution precursors were formulated for the printing of microdot arrays of different compositions in the above oxide systems. Microdot arrays were successfully printed on C-cut and R-cut sapphire substrates using Biodot printer at Los Alamos National Laboratory (LANL). The microdot arrays were adherent and stable after heat-treating at 1665 C and had an average thickness of around 2 (micro)m. X-ray fluorescence elemental mapping showed the arrays to be of the correct chemical composition. Sintered microdots were found to be highly crystalline by microscopic observation and X-ray diffraction. Scintillation was not clearly detectable by visual observation under UV illumination and by video observation under the scanning electron beam of an SEM. The microdots were either poorly scintillating or not scintillating under the present synthesis and testing conditions. Further improvements in the synthesis and processing of the microdot arrays as well as extensive scintillation testing are needed