Electron Microscopy and Raman Spectroscopy Study of Pu-Bearing LaBS Glasses

Abstract

ABSTRACTTwo LaBS glasses containing 9.5 wt.% (#1) and 5.0 wt.% PuO2 (#2) were prepared by melting in Pt ampoules at 1500 C and examined by scanning electron microscopy with energy dispersive X-ray spectroscopy. The bulk of sample #1, both as-prepared and stored for 3 yrs, was amorphous with homogeneous PuO2 distribution. Sample #2, especially after storage for 2-3 yrs, was partly devitrified primarily in the near-surface area. As followed from X-ray elemental maps, the vitreous phase was enriched with Al and Si whereas larger elongated and smaller dendrite crystals strongly enriched with rare earths (La, Nd, Gd) and Si and minor amounts of Hf may be attributed to britholite. A minor concentration of Pu was also observed in this phase. Moreover, relatively minor amounts of white regular crystals with high PuO2 and lower HfO2 contents were observed in the samples and are probably associated with PuO2 and a PuO2-HfO2 cubic solid solution phase. Nevertheless, even in devitrified areas of the samples, the majority of the Pu remained in the vitreous phase where it was homogeneously distributed.