Synthesis and Phase Identification of Lithium Gallium Oxide Compositions for Scintillator Applications

Investigation into new scintillation materials can be time consuming and costly; however, creating sintered pellets as a screening method can be a time- and cost-efficient alternative. In this study, pellets of three different cerium doped lithium gallium oxide compounds were synthesized. Compositions of LiGaO2:Ce, Li5GaO4:Ce, and LiGa5O8:Ce were created from combining Li2CO3, Ga2O3 and CeO2 at different stoichiometric ratios, assuming the CO2 produced would burn off, and aiming to use 0.5% cerium by weight. These mixtures were made into pellets and sintered. The sintering temperatures of LiGaO2 and LiGa5O8 used were based on the principle of being 2/3 the melting temperatures. The sintering temperatures used for LiGaO2 and LiGa5O8 were 1100ºC and 987ºC, respectively. The sintering of Li5GaO4 was investigated at 1100ºC, 800ºC, and 500ºC. The only temperature tested that did not melt the Li5GaO4 pellets was 500ºC. X-ray diffraction and phase identification were used to find the given phase of each compound. The phase of LiGaO2 has shown to be the right phase, while LiGa5O8 had an abundance of Ga2O3 and LiGa5O8, and Li5GaO4 showed an excess of LiGaO2. Radioluminescence was used to determine the emission wavelength of these compounds, providing the importance of sintering pellets more than once with the LiGa5O8 data.