Yttrium aluminum garnet Nanoparticles with low antisite Defects studied with neutron and X-ray diffraction

The presence of cation antisite defects is considered to be one of the most important factors determining the fluorescence, laser, and scintillation properties of rare earth-doped yttrium aluminum garnet (YAG) materials. However, no direct evidence or systematic investigation of antisite defect evolution as a function of cation composition variation in YAG has been reported in the previous literature. In this paper, we report a combined neutron and X-ray diffraction investigation on cation antisite defects performed on specially synthesized nonstoichiometric yttrium aluminum garnet nanoparticles to try to understand the defect chemistry in the YAG system. No evidence was found for YAl,16a, YAl,24d and AlY,24c antisite defects in these specially fabricated samples within the limit of diffraction techniques. The results suggest that YAG materials containing low level or no antisite defects can be achieved through low temperature synthesis process.

Graphical AbstractThrough combined Rietveld refinement against both the NPD and XRD data, no or low level antisite defect exists in the low temperature synthesized YAG powders, bond lengths are changeless as a function of the nominal Y/Al ratio, nonstoichiometry has little influence on antisite defect formation.Figure optionsDownload as PowerPoint slideHighlights
► Defects investigation with combined Rietveld refinement of NPD and XRD.
► No or less than 2at% for YAl,16a and YAl,24d antisite defects.
► Nonstoichiometry has little influence on antisite defect formation.