Title: Inelastic neutron scattering evidence for anomalous H–H distances in metal hydrides

Abstract

Hydrogen-containing materials are of basic as well as technological interest. An outstanding question for both is the amount of hydrogen that can be incorporated in such materials, because that determines dramatically their physical properties such as electronic and crystalline structure. The number of hydrogen atoms in a metal is controlled by the interaction of hydrogens with the metal and by the hydrogen–hydrogen interactions. It is well established that the minimal possible hydrogen–hydrogen distances in conventional metal hydrides are around 2.1 Å under ambient conditions, although closer H–H distances are possible for materials under high pressure. We introduce inelastic neutron scattering measurements on hydrogen in ${\mathrm{Z}\mathrm{r}\mathrm{V}}_2{\mathrm{H}}_x$showing nonexpected scattering at low-energy transfer. The analysis of the spectra reveals that these spectral features in part originate from hydrogen vibrations confined by neighboring hydrogen at distances as short as 1.6 Å. These distances are much smaller than those found in related hydrides, thereby violating the so-called Switendick criterion. The results have implications for the design and creation of hydrides with additional properties and applications.

Authors:

Borgschulte, Andreas  ^[1];

• Search DOE PAGES for author "Borgschulte, Andreas"
• Search DOE PAGES for ORCID "0000-0001-6250-4667"

Terreni, Jasmin ^[1]; Billeter, Emanuel ^[1]; Daemen, Luke ^[2]; Cheng, Yongqiang  ^[2];

• Search DOE PAGES for author "Cheng, Yongqiang"
• Search DOE PAGES for ORCID "0000-0002-3263-4812"

Pandey, Anup ^[2]; Łodziana, Zbigniew ^[3]; Hemley, Russell J.  ^[4];

• Search DOE PAGES for author "Hemley, Russell J."
• Search DOE PAGES for ORCID "0000-0001-7398-8521"

Ramirez-Cuesta, Anibal J.  ^[2]

• Search DOE PAGES for author "Ramirez-Cuesta, Anibal J."
• Search DOE PAGES for ORCID "0000-0003-1231-0068"

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+ Show Author Affiliations

1. Federal Inst. of Technology, Zurich (Switzerland)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
3. Polish Academy of Sciences (PAS), Krakow (Poland)
4. Univ. of Illinois, Chicago, IL (United States)

Publication Date:

Thu Feb 06 00:00:00 EST 2020

Research Org.:

George Washington Univ., Washington, DC (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP); National Science Foundation (NSF); Swiss National Science Foundation (SNSF); USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1599880

Grant/Contract Number:  

NA0003858; AC05-00OR22725; DMR-1809783

Resource Type:

Accepted Manuscript

Journal Name:

Proceedings of the National Academy of Sciences of the United States of America

Additional Journal Information:

Journal Volume: 117; Journal Issue: 8; Journal ID: ISSN 0027-8424

Publisher:

National Academy of Sciences

Country of Publication:

United States

Language:

English

Subject:

74 ATOMIC AND MOLECULAR PHYSICS; intermetallic hydrides; hydrogen correlation; Switendick criterion; inelastic neutron scattering; diffusion