Combinatorial Thin Film Synthesis of Cerium Doped Scintillation Materials in the Lutetium Oxide—Silicon Oxide System

The search for new scintillator crystals can be limited by the time consuming nature of the crystal growth process. In this paper, we demonstrate the use of a combinatorial thin film synthesis technique that is being used to explore new scintillator materials. The combinatorial synthesis process utilizes up to four individual R.F. magnetron sputtering sources which can be simultaneously powered to generate a wide composition space of binary, ternary, or quaternary material systems. In this work, we have investigated the lutetium oxide (Lu₂O₃)-silicon oxide (SiO₂) material system doped with cerium. Lu₂SiO_5-doped with cerium has been thoroughly characterized due to its use in PET imaging and provides a good benchmark for our proposed approach. Thin film, cerium doped lutetium oxide-silicon oxide gradients were synthesized to investigate the phases of the material system that exhibit scintillation properties and the results were compared to the results of bulk crystal samples. We have found that the emission spectra of the thin film materials have similar characteristics compared to the bulk crystals. Additionally, X-ray diffraction measurements have been correlated to the anticipated phases of the equilibrium phase diagram, and the intensity of the luminescence emission spectra have been correlated with the corresponding phases of the system.