Fabrication and characterization of uranium–thorium–zirconium hydrides

Abstract Two uranium–thorium–zirconium hydrides, (UTh 4 Zr 10 )H 1.9 and (U 4 Th 2 Zr 9 )H 1.5 , 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 (ZrH 1.6+ x ), thorium–zirconium hydride (ThZr 2 H 7− x ), and uranium metal. The elastic modulus was mapped across the microstructure using nanoscale dynamic stiffness mapping. The elastic modulus of ThZr 2 H 7− x phase is found to be 172 GPa.