Crystallization control toward colorless cerium-doped scintillating glass

Abstract

The construction of cerium-doped materials is of great technological importance for various applications, including smart lighting, biological shielding and high-energy ray and particle detection. A major challenge is the efficient prevention of the undesired colorization after cerium doping. Here we present the nanocrystallization method for constructing colorless cerium-doped glass with extremely high cerium concentration (15 mol%). The structure and optical characterizations confirm that the notable color change of glass is associated with the precipitation of CeF crystalline phase during heat-treatment. The chemical state investigation shows that most of cerium ions exist in the form of Ce in both the glass and glass-ceramic samples. The chemical environment study indicates a dramatic change in the local structure unit from -Ce-O- to -Ce-F-, which is believed to dominate the decoloring phenomenon in cerium doped glass. As a result, a significant improvement in the ultraviolet excited luminescence (~35 times enhancement in intensity) and scintillating performance can be achieved, pointing to potential applications in X-ray detection.

Structure and vibrations of cerium in silica glass from molecular dynamics simulations

“…Cerium-containing glasses have stimulated extensive research interest due to their broad applications in radiation dosimetry and optical engineering. [1][2][3][4][5][6] Exhibiting unique separations between the 5d and 4f energy levels of Ce ions, these materials are commonly used for particle detectors and laser activators. In particular, Ce-doped silica has recently been proposed as a candidate absorber for the inertial confinement fusion facilities to protect the transport mirrors from laser back-reflection, which inclines to damage the surfaces and enforce frequent exchanges of optics consequently.…”

Hybridized oxyfluoride photonic glasses for radiation detection

“…29 Moreover, the strong reduction ability of F − is also favorable for reduction of Ce 4+ into Ce 3+ , thus contributing to the blueshift of the cutoff wavelength. 30 All of the glass samples exhibit intense blue luminescence under excitation with the ultraviolet light, as indicated in Figure 4A, B. The corresponding emission spectra are shown in Figure 4C, D. They are characterized by the broad emission bands with the central wavelength at ~420 and ~410 nm for BaO-SiO 2 and BaO-BaF 2 -SiO 2 system, respectively, which are originated from the 5d → 4f electronic transition of Ce 3+ .…”

“…This can also be understood by the fact that the relatively low optical basicity of BaF 2 (0.5) component 29 . Moreover, the strong reduction ability of F − is also favorable for reduction of Ce 4+ into Ce 3+ , thus contributing to the blueshift of the cutoff wavelength 30 …”

“…On the one hand, the addition of F can create special local environment with low phonon energy, 32 thus favorable for improving the radiative transition. On the other hand, F is supposed to be helpful for transformation of Ce 4+ into Ce 3+ , resulting in the increase in the content of active centers 30 …”

“…On the other hand, F is supposed to be helpful for transformation of Ce 4+ into Ce 3+ , resulting in the increase in the content of active centers. 30 The X-ray-induced luminescence was characterized and the corresponding spectra are summarized in Figure 5. Similar to the ultraviolet light-induced photoluminescence, the luminescence spectra are characterized by a broadband emission band at ~420 nm and 410 nm for BaO-SiO 2 and BaO-BaF 2 -SiO 2 system, respectively ( Figure 5A, B), which is also associated with the 5d → 4f electronic transition of Ce 3+ .…”