Optical, scintillation and radiation tolerance properties of Pr-doped pyrosilicate crystals

A series of Pr-doped pyrosilicate crystals, Y2Si2O7 (YPS), Pr2Si2O7 (PrPS), Gd2Si2O7 (GPS), and Lu2Si2O7 (LPS), were synthesized by the floating zone (FZ) method to investigate whether the positive hysteresis phenomenon was observed or not. In all crystals, no impurity phases were observed in X-ray diffraction (XRD) analyses. In photoluminescence (PL) spectra, Pr3+ 5d–4f emission was observed from 270 to 400 nm in all the samples, and the PL decay times of them were around 10 ns. In radioluminescence (RL) spectra, they showed Pr3+ 5d–4f emission from 270 to 400 nm in all the samples, and the scintillation decay times were around 20 ns. When we irradiated with γ-rays from 137Cs, the scintillation light yields of YPS, GPS, and LPS were 8300, 1800, and 9700 ph/MeV, respectively. After these basic characterizations, we irradiated 0, 200, and 400 Gy γ-rays exposure by using 60Co. As a result, the positive hysteresis was not observed and YPS and LPS showed relatively high radiation resistivity.