Optical and Scintillation Properties of Rare-Earth Ion-Doped 12CaO·7Al2O3 Single Crystals

Abstract

We have synthesized undoped and rare-earth (RE)-doped 12CaO•7Al 2 O 3 (RE:C12A7) crystals by the floating zone (FZ) method to systematically study the effects of RE doping (doped with all the lanthanoid elements except for Sc, Y, La, Pm, and Lu) in C12A7 for radiation detector applications.In both photoluminescence (PL) and scintillation, the undoped C12A7 crystal showed a weak emission due to the lattice defects appearing at around 500 nm, and the decay time was on the order of several nanoseconds.On the other hand, the RE:C12A7 crystals showed PL and scintillation owing to the 4f-4f transitions of RE 3+ ions appearing from the UV to NIR ranges depending on the RE element.The decay times of these emissions ranged from a few microseconds to milliseconds depending on the RE element and the values were typical for the electronic transitions of trivalent rare earths.