Experimental signatures of interstitial electron density in transparent dense sodium
The transparent <i>hP</i>4 phase of dense sodium (Na), stable above 200 GPa, has been computed to be an electride in which valence electrons are localised on interstitial lattice sites within the structure. However, there is no experimental evidence for this interstitial electron localisation in Na, or indeed in other high-density electride phases. Using static compression and single-crystal X-ray diffraction techniques, we have grown and studied a single-crystal sample of Na in the <i>hP</i>4 phase at 223 GPa. Using atomic form factors for <i>hP</i>4-Na derived from quantum crystallography techniques, we present experimental results to support the electride nature of this phase.
Authors
- Eva Zurek (ORCID: https://orcid.org/0000-0003-0738-867X)
- C. V. Storm (ORCID: https://orcid.org/0000-0002-5497-4404)
- M. I. McMahon (ORCID: https://orcid.org/0000-0003-4343-344X)
- Stefano Racioppi (ORCID: https://orcid.org/0000-0002-4174-1732)
- M. J. Duff (ORCID: https://orcid.org/0000-0002-0745-0157)
- J. McHardy (ORCID: https://orcid.org/0000-0002-2630-8092)
Institutions
- Buffalo State University (US)
- University at Buffalo, State University of New York (US)
- University of Edinburgh (GB)
Publication Details
- Journal
- Communications Materials
- Published
- 2025-09-01
- DOI
- https://doi.org/10.1038/s43246-025-00925-w
- Citations
- 1
- Primary Topic
- Ammonia Synthesis and Nitrogen Reduction
- Type
- article
- Field-Weighted Citation Impact
- 0.39
Funders
- National Science Foundation
- U.S. Department of Energy
- European Synchrotron Radiation Facility
- Office of Science
- Engineering and Physical Sciences Research Council
- Deutsches Elektronen-Synchrotron
- Fusion Energy Sciences