Description
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.
Details
Title
- Twinning of cubic diamond explains reported nanodiamond polymorphs
Contributors
- Nemeth, Peter (Author)
- Garvie, Laurence (Author)
- Buseck, Peter (Author)
- College of Liberal Arts and Sciences (Contributor)
- School of Earth and Space Exploration (Contributor)
- Center for Meteorite Studies (Contributor)
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2015-12-16
Resource Type
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Identifier
- Digital object identifier: 10.1038/srep18381
- Identifier TypeInternational standard serial numberIdentifier Value2045-2322
Note
- The final version of this article, as published in Scientific Reports, can be viewed online at: https://www.nature.com/articles/srep18381
Citation and reuse
Cite this item
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Németh, P., Garvie, L. A., & Buseck, P. R. (2015). Twinning of cubic diamond explains reported nanodiamond polymorphs. Scientific Reports, 5(1). doi:10.1038/srep18381