Unique Nanomechanical Properties of Diamond–Lonsdaleite Biphases: Combined Experimental and Theoretical Consideration of Popigai Impact Diamonds
| Autor: | Kirill V. Yusenko, Alexander S. Sukhikh, S. A. Gromilov, Evgenia A. Kovaleva, Paul Avramov, Vladimir A. Pomogaev, Artem V. Kuklin, Woohyeon Baek, Iuliia Melchakova, Alexandr S. Fedorov, Michael Hanfland |
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| Rok vydání: | 2019 |
| Předmět: |
Diffraction
Bulk modulus Materials science Mechanical Engineering Material properties of diamond Diamond Lonsdaleite Bioengineering 02 engineering and technology General Chemistry engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Molecular physics Matrix (geology) Impact crater engineering General Materials Science Density functional theory 0210 nano-technology |
| Zdroj: | Nano Letters. 19:1570-1576 |
| ISSN: | 1530-6992 1530-6984 |
| DOI: | 10.1021/acs.nanolett.8b04421 |
| Popis: | For the first time, lonsdaleite-rich impact diamonds from one of the largest Popigai impact crater (Northern Siberia) with a high concentration of structural defects are investigated under hydrostatic compression up to 25 GPa. It is found that, depending on the nature of a sample, the bulk modulus for lonsdaleite experimentally obtained by X-ray diffraction in diamond-anvil cells is systematically lower and equal to 93.3-100.5% of the average values of the bulk moduli of a diamond matrix. Density functional theory calculations reveal possible coexistence of a number of diamond/lonsdaleite and twin diamond biphases. Among the different mutual configurations, separate inclusions of one lonsdaleite (001) plane per four diamond (111) demonstrate the lowest energy per carbon atom, suggesting a favorable formation of single-layer lonsdaleite (001) fragments inserted in the diamond matrix. Calculated formation energies and experimental diamond (311) and lonsdaleite (331) powder X-ray diffraction patterns indicate that all biphases could be formed under high-temperature, high-pressure conditions. Following the equation of states, the bulk modulus of the diamond (111)/lonsdaleite (001) biphase is the largest one among all bulk moduli, including pristine diamond and lonsdaleite. |
| Databáze: | OpenAIRE |
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