Incoherent Quasielastic Neutron Scattering study of hydrogen diffusion in thorium–zirconium hydrides

Monophase thorium–zirconium hydrides (ThZr2Hx) have been fabricated starting from a metallic alloy and the hydrogen stoichiometry determined by X-ray diffraction. Incoherent Quasielastic Neutron Scattering (IQNS) on the hydrides was conducted over the temperature range 650–750 K at the Backscattering Silicon Spectrometer (BASIS) at the Spallation Neutron Source (SNS) at ORNL. The isotropic Chudley–Elliott model was utilized to analyze the quasielastic linewidth broadening data as function of momentum transfer. The diffusion coefficient and average jump distance of hydrogen atoms in ThZr2H5.6 and ThZr2H6.2 were extracted from the measurements.