Correlation effects on stability in Pu metal and its alloys

摘要

The existence of six crystallographic allotropes from room temperature up to the solid-liquid transition just above 913 K at atmospheric pressure makes solid Plutonium unique among the elements in the periodic table. Among these phases (labeled (alpha), (beta), (gamma), (delta)(delta)(prime)), and (var-epsilon), the (delta) phase, stable between 593 K and 736 K, has commanded considerable interest in the metallurgical and solid state communities. In contrast to the low-temperature monoclinic (alpha) phase, which is brittle, the face-centered cubic (fcc) (delta) phase is ductile, a property that makes it convenient for engineering applications. This phase can also be stabilized through alloying with a number of other elements such as Ga, Al, Sc, and Am.