Investigation of the scintillation properties of LuAG:Tb~(3+) nanocrystalline powders and nanoceramic prepared by SPS method

摘要

1 mole percent Tb~(3+) doped lutetium aluminium garnet (LuAG:Tb~(3+)) nanocrystalline powders were prepared by Pechini method. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurements confirmed the atomic binding energy and crystal structure. The XRD results showed that the nanocrystalline powders had cubic structure with grain sizes of 11 and 34 nm at minimum and maximum annealing temperatures, respectively. The morphology of the nanocrystalline powders with grain sizes 11 and 34 nm was characterized by transmission electron microscopy (TEM) analysis. The UV-Vis-NIR analyses were done to obtain energy absorption values and to investigate the effect of different grain sizes on absorption spectra of nanocrystalline powders. Excitation, emission spectra and decay time were measured for different grain sizes of the nanocrystalline powders. The results showed that increasing grain size was caused an increasing in emission intensity. The different grain sizes and quenching parameter such as an OH group affected the decay time of the LuAG:Tb~(3+) nanocrystalline powders. Then the LuAG:Tb~(3+) nanoceramics were fabricated at 1500℃ by spark-plasma sintering (SPS) method for the first time from nanopowders prepared by the Pechini method at 900 ℃. The comparison of photoluminescence spectra and decay time of LuAG:Tb~(3+) powder and ceramic which were measured at room temperature in ultraviolet (VU) region, was done. Moreover, the X-ray excitation luminescence measurements of LuAG:Tb~(3+) nanoceramic were investigated.