2024-03-29T09:16:30Zhttps://keep.lib.asu.edu/oai/requestoai:keep.lib.asu.edu:node-1303122021-08-16T19:23:30Zoai_pmh:all130312
https://hdl.handle.net/2286/R.I.44400
NĂ©meth, P., Garvie, L. A., & Buseck, P. R. (2015). Twinning of cubic diamond explains reported nanodiamond polymorphs. Scientific Reports, 5(1). doi:10.1038/srep18381
10.1038/srep18381
2045-2322
http://rightsstatements.org/vocab/InC/1.0/
http://creativecommons.org/licenses/by/4.0
2015-12-16
8 pages
eng
Nemeth, Peter
Garvie, Laurence
Buseck, Peter
College of Liberal Arts and Sciences
School of Earth and Space Exploration
Center for Meteorite Studies
The final version of this article, as published in Scientific Reports, can be viewed online at: https://www.nature.com/articles/srep18381
The unusual physical properties and formation conditions attributed to h-, i-, m-, and n-nanodiamond polymorphs has resulted in their receiving much attention in the materials and planetary science literature. Their identification is based on diffraction features that are absent in ordinary cubic (c-) diamond (space group: Fd-3m). We show, using ultra-high-resolution transmission electron microscope (HRTEM) images of natural and synthetic nanodiamonds, that the diffraction features attributed to the reported polymorphs are consistent with c-diamond containing abundant defects. Combinations of {113} reflection and <011> rotation twins produce HRTEM images and d-spacings that match those attributed to h-, i-, and m-diamond. The diagnostic features of n-diamond in TEM images can arise from thickness effects of c-diamonds. Our data and interpretations strongly suggest that the reported nanodiamond polymorphs are in fact twinned c-diamond. We also report a new type of twin (<121> rotational), which can give rise to grains with dodecagonal symmetry. Our results show that twins are widespread in diamond nanocrystals. A high density of twins could strongly influence their applications.
Text
Twinning of cubic diamond explains reported nanodiamond polymorphs