The effect of annealing and ytterbium concentration on crystal structure and photoluminescence of Y3Al5O12:Yb nanopowders

Ytterbium-doped nanocrystalline powders of yttrium aluminum garnet (YAG:Yb3+) with ytterbium content from 5 to 30 at.% have been prepared by the citrate sol–gel method. Phase composition, crystal structure and microstructure of the materials were studied by means of X-ray powder diffraction techniques using both laboratory and synchrotron radiation sources. The photoluminescence spectra and the photoluminescence decay kinetics of Yb3+ ions at room temperature were performed as well. It was revealed that materials calcined at lower (1000 °C) temperature possess a small amount of Yb3+ ions occupying the octahedral sites of Al3+ ions, whereas the materials calcined at 1200 °C form the proper (Y1−xYbx)3Al5O12 solid solution.