High pressure stability of β-Zr: no evidence for isostructural phase transitions

ABSTRACT

Isostructural transitions have been reported to occur in several pure elements; however, most of these have been disproven. Zr is one of those elements which remains controversial with two reports of an isostructural bcc-to-bcc transition at ∼56–60 GPa at an ambient temperature and a more recent report proposing a second bcc-to-bcc transition at 110 GPa. Here, we report a detailed experimental and theoretical study of zirconium in the pressure region of the proposed isostructural transition(s). We conducted three room temperature static compression experiments using Ne as a pressure transmitting medium up to 80 GPa. We see no evidence for an isostructural transition finding a smooth compression curve for β-Zr. We determined the theoretical volume, elastic parameters, and Poisson’s ratio for β-Zr up to 717 GPa and no obvious anomalies are identified. Our new results join the growing body of evidence that does not find evidence of isostructural transitions in β-Zr.

KEYWORDS:

• Diamond anvil cell
• high pressure
• isostructural phase transition
• X-ray diffraction

Acknowledgments

E.F. O’Bannon acknowledges helpful discussions with J. Jeffries, S. Anzellini, B. Sturtevant, and N. Big.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344 and was supported in part by the LLNL-LDRD program under project No. 17-ERD-038. Portions of this work were performed at HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory. HPCAT operations are supported by DOE-NNSA’s Office of Experimental Sciences. The Advanced Photon Source is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.