Thermal post-fabrication processing of Y2O 3:Tm ceramic scintillators

The effects of thermal post-fabrication processing in O2 flux on the luminescence and scintillation of Y2O3:Tm transparent ceramics were investigated. The material's microstructure, optical properties, and scintillation properties were characterized using X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, thermoluminescence measurements, differential pulse height distribution measurements, Archimedes density measurements, photoluminescence measurements, and ultra violet-visible transmission measurements. The processing is effective if performed in the time frame of 60-120mins at 1050°C under oxygen flow. After the first hour of processing, about 40% enhancement in the luminescence output together with about 20% enhancement in the scintillation light yield were observed. The enhancements were tentatively assigned to the incorporation of oxygen into vacancy sites. Longer cumulative processing times lead to the incorporation of oxygen as interstitials that is detrimental to scintillation light yield but not to luminescence output. This work also revealed that thermoluminescence measurements are a useful tool to predict scintillation light yield of Y 2O3:Tm.