Gallium preference for the occupation of tetrahedral sites in Lu3(Al5-xGax)O12multicomponent garnet scintillators according to solid-state nuclear magnetic resonance and density functional theory calculations

Abstract In this study, the distributions of aluminum and gallium atoms over the tetrahedral and octahedral sites in the garnet structure were investigated in mixed Lu3Al5-xGaxO12 crystals by using 27Al and 71Ga magic angle spinning nuclear magnetic resonance (NMR) and single crystal 71Ga NMR. The experimental study was supported by theoretical calculations based on density functional theory (DFT) in order to predict the trends in terms of the substitutions of Al by Ga in the mixed garnets. Both the experimental and theoretical results indicated the non-uniform distribution of Al and Ga over the tetrahedral and octahedral sites in the garnet structure, with a strong preference for Ga occupy…