Inelastic neutron scattering spectra of HxUO3

Abstract

Inelastic neutron scattering spectra have been recorded for the hydrogen insertion compounds δ-H_0.7UO₃, α-H_0.3UO₃ and α-H_1.1UO₃. Interpretation of the spectra in conjunction with infrared spectra leads to the conclusion that the two polymorphs of UO₃ behave differently on insertion of hydrogen. In δ-H_0.7UO₃ the hydrogen is attached solely in the form of OH groups, whereas the mode of attachment in δ-H_xUO₃ is dependent on the extent of insertion. At low degrees of reduction, the hydrogen is again attached as OH groups, whereas at high degrees of reduction the terminal oxygen of the parent oxide is attacked resulting in the formation of OH₂ groups.