LiPing Chen

Enhanced emissions in Tb3+-doped oxyfluoride scintillating glass ceramics containing KLu2F7 nano-crystals

Abstract KLu 2 F 7 : Tb 3+ oxyfluoride glass ceramics (GC) were successfully manufactured via traditional melt-quenching route with further heat-treatment. Their micro-structural and optical properties were systemically investigated by XRD, TEM, HRTEM techniques, transmittance spectra, excitation spectra, emission spectra, luminescence lifetime measurements and X-ray excited luminescence (XEL). Both photoluminescence and XEL of KLu 2 F 7 GC doped with Tb 3+ are highly enhanced after further heat-treatment resulting from the partition of Tb 3+ ions into the KLu 2 F 7 crystalline lattice with low phonon energy. Our investigation suggests that such Tb 3+ -doped transparent KLu 2 F 7 glass ceramics may present potential application in X-ray scintillator for slow event detection.

Enhanced emissions in self-crystallized oxyfluoride scintillating glass ceramics containing KTb 2 F 7 nanocrystals

Self-crystallized KTb2F7 oxy-fluoride glass ceramics (GC) were successfully manufactured via the traditional melt-quenching method. KTb2F7 nanocrystals were already formed after melt-quenching, which is beneficial to the realization of controllable glass crystallization to some degree for affording desirable nano-crystal size and activator partition. Their microstructural and optical properties were systemically investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), absorption spectra, photoluminescence (PL), luminescence lifetime measurements and X-ray excited luminescence (XEL). Both PL and XEL of GC samples are highly enhanced because more nanocrystals formed and grew up after heat-treatment. Our investigation suggests that transparent KTb2F7 glass ceramics may present potential application in X-ray scintillator for X-ray imaging. And our strategy that takes active ions as host may contribute to designing other oxy-fluoride GC by using active ions as host.

Highly efficient Na_5Gd_9F_32:Tb^3+ glass ceramic as nanocomposite scintillator for X-ray imaging

Mono-crystal scintillator materials suffer from issues of complex, time-consuming techniques as well as small volume. Here, bulk Tb3+-doped Na5Gd9F32 glass ceramic (GC) scintillators with relatively high transparency were successfully manufactured via the melt-quenching method with further thermal treatment. Their structural and luminescent properties were systemically investigated by a series of characterization techniques including XRD, TEM, absorption spectra, photoluminescence (PL) excitation and emission spectra, lifetime measurements, and X-ray excited luminescence (XEL). Luminescent spectroscopy results show that the optimum doping concentrations of Tb3+ in precursor glass (PG) and GC systems are both 4 mol%. The XEL intensity of PG is about 64% of that of a commercial Bi4Ge3O14 (BGO) scintillator with the same thickness. Benefiting from the incorporation of Tb3+ ions into Na5Gd9F32 nanocrystals, enhanced PL and XEL of Tb3+ ion are realized after crystallization. The internal PL quantum yield of GC is 43.0% and the XEL intensity of GC reaches 130% of that of a BGO scintillator. Our results demonstrate that Na5Gd9F32 GC may act as an efficient scintillator with large-volume and low-cost.