同位素对吸附量子相的影响：H₂ 和 D₂ 在纳米多孔碳中的扩散

Isotope effect on adsorbed quantum phases: diffusion of H2 and D2 in nanoporous carbon.

作者信息

Contescu Cristian I, Zhang Hongxin, Olsen Raina J, Mamontov Eugene, Morris James R, Gallego Nidia C

机构信息

Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

Neutron Scattering Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

出版信息

Phys Rev Lett. 2013 Jun 7;110(23):236102. doi: 10.1103/PhysRevLett.110.236102.

DOI:10.1103/PhysRevLett.110.236102

PMID:25167516

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.

摘要

在10至40K温度下，对同一纳米多孔碳中的H₂和D₂进行准弹性中子散射实验，结果表明存在极端的量子筛分效应，D₂的扩散速度比H₂快76倍。D₂表现出类似液体的扩散，而H₂则呈现出Chudley-Elliott跳跃扩散，这证明了由于分子间相互作用的量子效应，它们与吸附位点局部晶格的关系不同。H₂的扩散起始温度为22至25K，D₂为10至13K。在这些温度下，H₂和D₂具有相同的热德布罗意波长，该波长与主要孔径相关。