title: Isotope effect on adsorbed quantum phases: diffusion of H2 and D2 in nanoporous carbon.
abstract: Quasielastic neutron scattering of H(2) and D(2) in the same nanoporous carbon at 10-40 K demonstrates extreme quantum sieving, with D(2) diffusing up to 76 times faster. D(2) also shows liquidlike diffusion while H(2) exhibits Chudley-Elliott jump diffusion, evidence of their different relationships with the local lattice of adsorption sites due to quantum effects on intermolecular interactions. The onset of diffusion occurs at 22-25 K for H(2) and 10-13 K for D(2). At these temperatures, H(2) and D(2) have identical thermal de Broglie wavelengths that correlate with the dominant pore size.
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Cristian I
authors.initials: CI
authors.lastname: Contescu
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Hongxin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Raina J
authors.initials: RJ
authors.lastname: Olsen
authors.affiliation: Neutron Scattering Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Mamontov
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Morris
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Nidia C
authors.initials: NC
authors.lastname: Gallego