Zirconium hydride thermal scattering law

Abstract

The aim of this paper is to evaluate the thermal neutron scattering properties of zirconium hydride (ZrH_x) with particular emphasis on the ε-phase (x = 2) and the δ-phase (x = 1.5). The methodology involved performing density functional theory calculations using the VASP code to obtain the force constants. Subsequently, the Phonopy and NJOY codes were used to analyse the lattice dynamics and thermal scattering properties. The main results of this investigation include a detailed study of the atomic structures, mechanical properties, phonon density of states, thermal scattering cross sections and benchmark results. These results are compared with other calculations from the literature and experimental measurements. The assessment at the Jožef Stefan Institute (JSI) generally reduces the discrepancies in benchmark results, but certain inconsistencies remain. The addition of the data for zirconium bound in ZrH to the analysis has no appreciable effect on the benchmark results.