Synthesis, structural investigation and luminescence spectroscopy of nanocrystalline Gd3Ga5O12 doped with lanthanide ions

Gadolinium gallium garnet (GGG) nanocrystalline powder doped with. lanthanide ions (Eu3+ and Er3+) have been obtained using two different methods (coprecipitation and Pechini). The X-ray diffraction results show that single phase cubic GGG nanopowders have been obtained for both preparation methods. The samples prepared by the two procedures show different morphologies, as revealed by scanning electron microscopy images. The Er3+-doped nanopowders obtained with the coprecipitation method show strong luminescence upon 488.0 nm excitation. The emission spectrum is similar to the one of the single crystal and of nanopowders of the same composition prepared by a combustion synthesis. The Er3+-doped GGG nanopowders obtained by the coprecipitation method show efficient upconversion in the green region (around 550 nm) upon excitation in the near IR at a wavelength of 800 nm