Excited-state vibrational tunnel splitting of hydrogen trapped by nitrogen in niobium

J. J. Rush; T. J. Udovic; N. F. Berk; D. Richter; A. Magerl

doi:10.1209/epl/i1999-00465-1

All issues

Volume 48 / No 2 (October II 1999)

Europhys. Lett., 48 2 (1999) 187-193

Abstract

Issue		Europhys. Lett. Volume 48, Number 2, October II 1999


Page(s)		187 - 193
Section		Condensed matter: structure, mechanical and thermal properties
DOI		https://doi.org/10.1209/epl/i1999-00465-1
Published online		01 September 2002

Europhys. Lett., 48 (2), pp. 187-193 (1999)

Excited-state vibrational tunnel splitting of hydrogen trapped by nitrogen in niobium

J. J. Rush¹, T. J. Udovic¹, N. F. Berk¹, D. Richter² and A. Magerl³

¹ NIST Center for Neutron Research, National Institute of Standards and Technology Gaithersburg, MD 20899, USA
² Institut für Festkörperforschung, Forschungszentrum Jülich GmbH D-52425 Jülich, Germany
³ Lehrstuhl für Kristallographie und Strukturphysik, Universität Erlangen-Nürnberg Bismarckstrasse 10, D-91054 Erlangen, Germany

Received: 25 September 1998
Accepted: 30 August 1999

Abstract

High-resolution inelastic-neutron-scattering spectra of hydrogen trapped by interstitial nitrogen impurities in $\rm NbN_{0.007}H_{0.004}$ have been measured to study the vibrational lineshape of the broad $\rm 105$ $\rm meV$ feature previously observed for $\rm NbN_{0.004}H_{0.003}$ . The spectrum measured at $\rm 4.2\;K$ exhibits clear evidence of a doublet that disappears at higher temperatures. We interpret this result as the first spectroscopic observation of excited-state tunnel splitting of light-atom (H) vibrations in a solid-state double-well potential. We also show that both the observed excited-state splitting of $\rm 4.0 \pm 0.3\;meV$ and the previously measured ground-state splitting are well represented by a hardened-harmonic-well potential.

PACS: 66.35.+a – Quantum tunneling of defects / 34.20.Cf – Interatomic potentials and forces / 61.12.Ex – Neutron scattering techniques (including small-angle scattering)

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.