Pressure-induced reconstructive phase transition in Cd3As2

Monika Gamza, Paolo Abrami, Lawrence V.D. Gammond, Jake Ayres, Israel Osmond, Takaki Muramatsu, Robert Armstrong, Hugh Perryman, Dominik Daisenberger, Sitikantha Das, Sven Friedemann*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Cadmium arsenide (Cd3As2) hosts massless Dirac electrons in its ambient-condition tetragonal phase. We report x-ray diffraction and electrical resistivity measurements of Cd3As2 upon cycling pressure beyond the critical pressure of the tetragonal phase and back to ambient conditions. We find that, at room temperature, the transition between the low- and high-pressure phases results in large microstrain and reduced crystallite size, both on rising and falling pressure. This leads to nonreversible electronic properties, including self-doping associated with defects and a reduction of the electron mobility by an order of magnitude due to increased scattering. This paper indicates that the structural transformation is sluggish and shows a sizable hysteresis of over 1 GPa. Therefore, we conclude that the transition is first-order reconstructive, with chemical bonds being broken and rearranged in the high-pressure phase. Using the diffraction measurements, we demonstrate that annealing at ∼200 ∘C greatly improves the crystallinity of the high-pressure phase. We show that its Bragg peaks can be indexed as a primitive orthorhombic lattice with aHP≈8.68 Å, bHP≈17.15 Å, and cHP≈18.58 Å. The diffraction study indicates that, during the structural transformation, a new phase with another primitive orthorhombic structure may also be stabilized by deviatoric stress, providing an additional venue for tuning the unconventional electronic states in Cd3As2.

Original languageEnglish
Article number024209
JournalPhysical Review Materials
Volume5
Issue number2
DOIs
Publication statusPublished - Feb 2021

Bibliographical note

Funding Information:
The authors would like to thank Ingo Loa for valuable discussion and Charles Clapham and Chris Bell for technical support. This paper was partially supported by the EPSRC under Grants No. EP/R011141/1, No. EP/L025736/1, No. EP/N026691/1, as well as the ERC Horizon 2020 programme under Grant No. 715262-HPSuper. We acknowledge Diamond Light Source for time on beamline I15 under proposal EE19319-1.

Publisher Copyright:
© 2021 American Physical Society.

Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.

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