Extreme Static Compression of Carbon to Terapascal Pressures
Document Type
Article
Publication Date
12-3-2018
Publication Title
Carbon
Volume
144
First page number:
161
Last page number:
170
Abstract
Recent reports of record-setting ultrahigh static pressures achieved in diamond anvil cells (DACs, 495 GPa) and double-stage DACs (ds-DACs, 1 TPa) raise fundamental questions about mechanical response of diamond and related carbon structures under extreme compression. Here we present results from a combined first-principles calculation and finite-element analysis that unveil the mechanisms responsible for the greatly enhanced compressive strengths of these carbon structures by lateral confining stressesconcentrated near anvil tips, stemming from structural deformationsin compressed DACs and further strengthened by additional confining pressures in ds-DACs. Our results indicate that diamond anvils oriented in the [001] direction with a flat culet diameter of 20 μm can sustain peak pressures above 500 GPa, vastly exceeding its pure compressive strength of about 200 GPa. Among nano-carbon structures with enhanced shear strengths by nano- or grain-boundaries, we find that nano-twinned diamond possesses the highest compressive strength, reaching 1 TPa in ds-DAC settings, in agreement with experimental observations. The present findings establish key benchmarks and expand the realm of understanding of diamond and related carbon structures under extreme loadingconditions; these results offer crucial insights for rational design of advanced and novel DAC devices.
Disciplines
Physics
Language
English
Repository Citation
Wu, H.,
Luo, X.,
Wen, L.,
Sun, H.,
Chen, C.
(2018).
Extreme Static Compression of Carbon to Terapascal Pressures.
Carbon, 144
161-170.
http://dx.doi.org/10.1016/j.carbon.2018.12.004