Pressure-induced bcc-rhombohedral phase transition in vanadium metal

DOI: 10.1103/PhysRevB.103.134103

Authors: M. G. Stevenson (The University of Edinburgh) , E. J. Pace (University of Edinburgh) , C. V. Storm (University of Edinburgh) , S. E. Finnegan (The University of Edinburgh) , G. Garbarino (European Synchrotron Radiation Facility) , C. W. Wilson (AWE) , D. Mcgonegle (AWE) , S. G. Macleod (AWE; The University of Edinburgh) , M. I. Mcmahon (University of Edinburgh)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Physical Review B , VOL 103

State: Published (Approved)
Published: April 2021

Abstract: Vanadium is reported to undergo a pressure-induced bcc-rhombohedral phase transition at 30–70 GPa, with a transition pressure that is sensitive to the hydrostaticity of the sample environment. However, the experimental evidence for the structure of the high-pressure phase being rhombohedral is surprisingly weak. We have restudied vanadium under pressure to 154 GPa using both polycrystalline and single-crystal samples, and a variety of different pressure transmitting media (PTM). We find that only when using single-crystal samples does one observe a rhombohedral high-pressure phase; the high-pressure diffraction profiles from the polycrystalline samples do not fit a rhombohedral lattice, irrespective of the PTM used. The single-crystal samples reveal two rhombohedral phases, with a continuous transition between them, and distortions from cubic symmetry are much smaller than previously calculated.

Journal Keywords: Phase transitions; Pressure effects

Subject Areas: Materials, Physics


Instruments: I15-Extreme Conditions

Other Facilities: ID15b at ESRF

Added On: 13/04/2021 10:05

Discipline Tags:

Physics Materials Science

Technical Tags:

Diffraction X-ray Powder Diffraction