Németh, Péter;
Garvie, Laurence AJ;
Salzmann, Christoph G;
(2023)
Canyon Diablo lonsdaleite is a nanocomposite containing c/h stacking disordered diamond and diaphite.
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
, 381
(2259)
, Article 20220344. 10.1098/rsta.2022.0344.
Preview |
Text
nemeth-et-al-2023-canyon-diablo-lonsdaleite-is-a-nanocomposite-containing-c-h-stacking-disordered-diamond-and-diaphite.pdf - Published Version Download (3MB) | Preview |
Abstract
In 1967, a diamond polymorph was reported from hard, diamond-like grains of the Canyon Diablo iron meteorite and named lonsdaleite. This mineral was defined and identified by powder X-ray diffraction (XRD) features that were indexed with a hexagonal unit cell. Since 1967, several natural and synthetic diamond-like materials with XRD data matching lonsdaleite have been reported and the name lonsdaleite was used interchangeably with hexagonal diamond. Its hexagonal structure was speculated to lead to physical properties superior to cubic diamond, and as such has stimulated attempts to synthesize lonsdaleite. Despite numerous reports, several recent studies have provided alternative explanations for the XRD, transmission electron microscopy and Raman data used to identify lonsdaleite. Here, we show that lonsdaleite from the Canyon Diablo diamond-like grains are a nanocomposite material dominated by subnanometre-scale cubic/hexagonal stacking disordered diamond and diaphite domains. These nanostructured elements are intimately intergrown, giving rise to structural features erroneously associated with h diamond. Our data suggest that the diffuse scattering in XRD and the hexagonal features in transmission electron microscopy images reported from various natural and laboratory-prepared samples that were previously used for lonsdaleite identification, in fact arise from cubic/hexagonal stacking disordered diamond and diaphite domains. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'.
| Type: | Article |
|---|---|
| Title: | Canyon Diablo lonsdaleite is a nanocomposite containing c/h stacking disordered diamond and diaphite |
| Location: | England |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1098/rsta.2022.0344 |
| Publisher version: | https://doi.org/10.1098/rsta.2022.0344 |
| Language: | English |
| Additional information: | © 2023 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. |
| Keywords: | diaphite, hexagonal diamond, lonsdaleite, nanocomposite, structural complexity |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10177233 |
Archive Staff Only
 |
View Item |
