Structural and luminescence study of Ce3+ and Tb3+ doped Ca3Sc2Si3O12 garnets obtained by freeze-drying synthesis method

Ca3Sc2Si3O12 garnets doped with Ce3+ and Tb3+ ions were synthesized by a freeze-drying precursor method. The structural characterization was performed by X-ray diffraction (XRD) and Raman spectroscopy. Scanning Electron Microscopy (SEM) images of the calcined material were studied. High temperature treatments and doping with RE3+ ions resulted in a reduction of the secondary phases (Sc2O3) and an increase of the mean size of the nanocrystals, from 75 to 149 nm. These effects were confirmed by means of Raman spectra. Moreover, luminescence features of Ce3+ and Tb3+ doped samples indicated that these ions are effectively incorporated into the crystalline phase. In addition, the energy transfer processes between Ce3+ and Tb3+ ions in codoped garnets have been studied.