Am phases in the matrix of a U-Pu-Zr alloy with Np, Am, and rare-earth elements

Planar features consisting of a central zone of ζ-(U, Np, Pu, Am) bracketed by zones of δ-(U, Np, Pu, Am)Zr2 bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ζ-(U, Np, Pu, Am) and δ-(U, Np, Pu, Am)Zr2. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.