Hydrogen Dynamics in Ce2Fe17H5: Inelastic and Quasielastic Neutron Scattering Studies

Published

September 21, 2011

Author(s)

Alexander V. Skripov, N. V. Mushnikov, P. B. Terent'ev, V. S. Gaviko, Terrence J. Udovic, John J. Rush

Abstract

The vibrational spectrum of hydrogen and parameters of H jump motion in the rhombohedral Th₂Zn₁₇d-type compound Ce₂Fe₁₇H₅ have been studied by means of inelastic and quasielastic neutron scattering. It is found that hydrogen atoms occupying interstitial Ce₂Fe₂ sites participate in the fast localized jump motion over the hexagons formed by these tetrahedral sites. The H jump rate τ-1 of this localized motion is found to change from 3.9x10⁹ s-1 at Τ = 140 K to 4.9x10¹¹ s-1 at Τ = 350 K, and the temperature dependence of τ-1 in the range (140-350) K is well described by the Arrhenius law with the activation energy of 103plus and minus}3 meV. Our results suggest that the hydrogen jump rate in Th₂Zn₁₇-type compounds strongly increases with decreasing nearest-neighbor distance between the tetrahedral sites within the hexagons. Since each such hexagon in Ce₂Fe₁₇H₅ is populated by two hydrogen atoms, the jump motion of H atoms on the same hexagon should be correlated.

Citation

Journal of Physics Condensed Matter

Volume

23

Pub Type

Journals

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Keywords

Ce2Fe17, hydrogen, hydrogen dynamics, inelastic neutron scattering, jump diffusion, localized motion, metal hydride, quasielastic neutron scattering, vibrational spectroscopy

Citation

Skripov, A. , Mushnikov, N. , Terent'ev, P. , Gaviko, V. , Udovic, T. and Rush, J. (2011), Hydrogen Dynamics in Ce₂Fe₁₇H₅: Inelastic and Quasielastic Neutron Scattering Studies, Journal of Physics Condensed Matter, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908701 (Accessed October 7, 2024)