Basic study of Eu2+-doped garnet ceramic scintillator produced by spark plasma sintering

Abstract We report a new discovery of Eu 2+ -doped bulk garnet ceramic scintillators based on reduction of Eu 3+ ions without additives. Eu 2+ -doped Y 3 Al 5 O 12 and Lu 3 Al 5 O 12 ceramics were prepared by spark plasma sintering (SPS) method. Using SPS, the green and blue luminescence was observed under UV lamp excitation for Eu 2+ -doped Y 3 Al 5 O 12 and Lu 3 Al 5 O 12 ceramics, respectively. Under excitation by 241 Am alpha-ray the Eu 2+ 5d–4f emission was observed in radioluminescence spectra both samples. For the first time, scintillation response due to Eu 2+ 5d–4f luminescence was observed in the bulk garnet oxide materials. In addition, Eu-doped Al 2 O 3 prepared by SPS showed Eu 2+ 5d–4f emission in the radioluminescence spectrum. It is confirmed that Al is a key element to reduce Eu 3+ as well as highly reductive condition in SPS.