Fabrication and characterization of uranium–thorium–zirconium hydrides

Two uranium–thorium–zirconium hydrides, (UTh4Zr10)H1.9 and (U4Th2Zr9)H1.5, have been fabricated and characterized. Fabrication involved arc melting of the constituent pure metals to form homogenous alloys, followed by hydriding at elevated temperatures in a hydrogen gas environment. The compounds were characterized by X-ray powder diffractometry as well as scanning and transmission electron microscopy. These methods revealed a multi-phase mixture of δ-zirconium hydride (ZrH1.6+x), thorium–zirconium hydride (ThZr2H7−x), and uranium metal. The elastic modulus was mapped across the microstructure using nanoscale dynamic stiffness mapping. The elastic modulus of ThZr2H7−x phase is found to be 172 GPa.