VUV- and X-ray-induced Properties of Lu2Si2O7, Y2Si2O7, and Gd2Si2O7 Single Crystals

Undoped Lu 2 Si 2 O 7 (LPS), Y 2 Si 2 O 7 (YPS), and Gd 2 Si 2 O 7 (GPS) single crystals are prepared by the floating-zone (FZ) method. The X-ray diffraction (XRD) patterns show the single phase of each material without any impurity phases. The luminescence properties of the samples are investigated under both vacuum ultraviolet (VUV) and X-ray excitation. When the samples are excited by VUV photons, intrinsic emission bands at 350-500, 320-480, and 310 nm are observed for LPS, YPS, and GPS, respectively. The X-ray-induced scintillation spectra have a similar spectral shape to those under excitation by VUV photons. The X-ray induced scintillation decay times of LPS and YPS are 48 and 13 s, respectively. For GPS, two scintillation decay constants of 169 s and 1 ms are observed.