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β-Technetium - An allotrope with a nonstandard volume-pressure relationship

MetadataDetails
Publication Date2021-06-09
JournalPhysical Review Materials
AuthorsEmily Siska, D. F. Smith, Christian Childs, Daniel Koury, Paul M. Forster
InstitutionsUniversity of Nevada, Las Vegas, Argonne National Laboratory
Citations3

In this work, we report the synthesis and structure of the second allotrope of technetium, β-Tc. Transformative pathways are accessed at extreme conditions using the laser-heated diamond anvil cell and confirmed with in situ synchrotron x-ray diffraction and Raman spectroscopy. βTc is fully recoverable to ambient conditions, although counter to our DFT calculations predicting a face-centered-cubic lattice, we observe a tetragonal structure (I4/mmm) that exhibits further tetragonal distortion with pressure. β-Tc has an expanded volume relative to the hcp ground state phase, that when doped with nitrogen has an unexpected volume lowering. Such anomalous behavior is possibly indicative of a rare electronic phase transition in a 4d element.

  1. 1997 - Chemistry of the Elements
  2. 2000 - Technetium [Crossref]
  3. 1986 - 3d, 4d and 5d Elements, Alloys and Compounds