The Effects of Cation Concentration in the Salt Solution on the Cerium Doped Gadolinium Gallium Aluminum Oxide Nanopowders Prepared by a Co-precipitation Method

Cerium doped gadolinium gallium aluminum oxide (GAGG:Ce) nanopowders were prepared by a co-precipitation method with different cation concentrations of the mother salt solution, followed by calcination at different temperatures. The influence of cation concentrations (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mol/L) in the mother salt solution on GAGG:Ce nanopowders was investigated by thermal gravity-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (IR), scanning electron microscopy (SEM), and photoluminescence spectroscopy (PL). The GAGG phase was formed after calcining at 950 degree C for 2 h for all samples. The primary particle sizes of powder calcined at the same temperature decrease with the increase of cation concentration, which is suggested by the analysis of SEM and specific surface area measurement. However, the nonuniformity of particle size was observed for samples prepared using the salt solutions with cation concentrations > 0.3 mol/L, especially for the 0.6 mol/L sample. The photoluminescence spectrum intensity indicates that the 0.2 mol/L and 0.3 mol/L samples have higher degree of crystal perfection than others. Considering all the factors above, samples synthesized by using salt solution with 0.3 mol/L cation concentration were chosen for ceramic scintillators preparation in our future work.