Cathodoluminescence characterization of defects in yttrium aluminum garnet doped with Nd

Nominally undoped and Nd-doped yttrium aluminum garnet (YAG) crystals were studied by scanning electron microscopy, electron probe x-ray microanalysis, and cathodoluminescence (CL) microscopy and spectroscopy techniques. The detection limit of CL for Nd in YAG was found to be 10-6 wt %. The nature of inhomogeneities in the crystals with a high Nd concentration was established. The distribution of background Nd impurity over defect-rich YAG crystals was assessed. A method for the identification of solid-phase inclusions from x-ray microanalysis and CL data is proposed. The effect of the growth technique and impurity concentration on the CL spectrum of YAG is examined.