Shear driven formation of nano-diamonds at sub-gigapascals and 300 K
Abstract
The transformation pathways of carbon at high pressures are of broad interest for synthesis of novel materials and for revealing the Earth's geological history. We have applied large plastic shear on graphite in a rotational anvil cell to form hexagonal diamond and nanocrystalline cubic diamond at extremely low pressures of 0.4 and 0.7 GPa, which are 50 and 100 times lower than the transformation pressures under hydrostatic compression and well below the phase equilibrium. Large shearing accompanied with pressure elevation to 3 GPa also leads to formation of a new orthorhombic diamond phase. Our results demonstrate new mechanisms and new means for plastic shear-controlled material synthesis at drastically reduced pressures, enabling new technologies for material synthesis. The result also has significant geological implications.
Additional Information
© 2019 Published by Elsevier Ltd. Received 7 December 2018, Revised 24 January 2019, Accepted 4 February 2019, Available online 6 February 2019. This work was supported by National Science Foundation (Grants No. DMR1431570, 1434613, and 1436985, managed by John Schlueter, and DMR1727428). V.I.L. and B.F. also acknowledge support from Army Research Office (Grant No. W911NF-17-1-0225 managed by David Stepp) and Vance Coffman Faculty Chair Professorship. Synchrotron X-ray experiment was performed at Cornell High Energy Synchrotron Source. The authors thank Dr. Zhongwu Wang for experimental technical support. The following is the Supplementary data to this article: Shear experiments details and diamond observation, index of the orthorhombic phase in comparison with the reported monoclinic phase, X-ray photon spectrum analysis of the sample before and after shear processing, determination of equilibrium stress under non-hydrostatic conditions, atomic simulations, instability stresses for pressure- and stress-induced transformations, molecular dynamics simulation, strain-induced transformations to and from amorphous phases, and micro- and macroscale modeling of strain-induced phase transformations between graphite and cubic diamond and hexagonal diamond [17,19,20,[34], [35], [36], [37], [38], [39]].Attached Files
Submitted - 1805.11239.pdf
Supplemental Material - 1-s2.0-S0008622319301253-mmc1.docx
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Additional details
- Eprint ID
- 92713
- Resolver ID
- CaltechAUTHORS:20190206-104941419
- DMR-1431570
- NSF
- DMR-1434613
- NSF
- DMR-1436985
- NSF
- DMR-1727428
- NSF
- W911NF-17-1-0225
- Army Research Office (ARO)
- Created
-
2019-02-06Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 1323