Crystal structure of high-Zr inclusions in an alloy containing U, Pu, Np, Am, Zr and rare-earth elements

Researchers commonly observe high-Zr inclusions in actinide-Zr alloys. As there is very little published data on the crystal structures of these inclusions, it has generally been assumed that the inclusions were impurity-stabilized ot-Zr. However, new electron-diffraction data from two high-Zr inclusions in an alloy containing Ii, Pu, Np, Am, Zr, and rare-earth elements show that these inclusions are not ot-Zr (which has a hexagonal structure) but, instead, have a face-centered cubic structure. This data is unique in that it combines single-crystal diffraction patterns and microchemical analyses from individual inclusions. More data on other high-Zr inclusions is clearly required. However, the present results suggest that caution is needed in assuming that all high-Zr inclusions in actinide-Zr alloys are ot-Zr. (C) 2014 Elsevier B.V. All rights reserved.