Comparative Study of Optical and Scintillation Properties of Tm-doped La2Si2O7 and Lu2Si2O7 Single Crystals

Abstract

Lanthanum and lutetium pyrosilicate (La2Si2O7 and Lu2Si2O7, respectively) single crystals with a Tm doping concentration of 2.0% were successfully synthesized by the floating-zone method. X-ray diffraction patterns showed a single phase in each compound without the impurity phase. Both their photoluminescence (PL) and scintillation properties were systematically determined in this study, including PL emission, PL decay time, X-ray-induced scintillation spectra, X-ray-induced scintillation decay time, afterglow level, and pulse height spectra. The emission from Tm3+ 4f–4f transition was observed on both samples as shown by PL emission as well as X-ray-induced scintillation spectra. Under 137Cs 662 keV γ-ray irradiation, their scintillation light yields were 2340 ph/MeV for Tm-doped Lu2Si2O7 and 1440 ph/MeV for Tm-doped La2Si2O7