title: Quasielastic neutron scattering study of hydrogen motion in NbC(0.71)H(0.28).
abstract: In order to study the mechanism and parameters of H jump motion in the nonstoichiometric Nb carbides, we have performed quasielastic neutron scattering (QENS) measurements for NbC(0.71)H(0.28) over the temperature range 11- 475 K. Our results indicate that about 30% of H atoms in this system participate in a fast diffusive motion. The temperature dependence of the corresponding H jump rate in the range 298-475 K follows the Arrhenius law with an activation energy of 328 ± 9 meV. The Q dependence of the QENS data suggests that the observed jump motion corresponds to long-range diffusion of H atoms along chains of the off-centre sites in carbon vacancies.
authors.affiliation: Institute of Metal Physics, Ural Division of the Russian Academy of Sciences, Ekaterinburg 620041, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Skripov
authors.forename: T J
authors.initials: TJ
authors.lastname: Udovic
authors.forename: J C
authors.initials: JC
authors.lastname: Cook
authors.forename: R
authors.initials: R
authors.lastname: Hempelmann
authors.forename: A A
authors.initials: AA
authors.lastname: Rempel
authors.forename: A I
authors.initials: AI
authors.lastname: Gusev