Pressure-induced phase transitions and superconductivity in magnesium carbides
SCIE
SCOPUS
- Title
- Pressure-induced phase transitions and superconductivity in magnesium carbides
- Authors
- Kim S.; Kim K.; Koo J.; Lee H.; Min B. I.; Kim D.Y.
- Date Issued
- 2019-12
- Publisher
- NATURE PUBLISHING GROUP
- Abstract
- Crystal structure prediction and in silico physical property observations guide experimental synthesis in high-pressure research. Here, we used magnesium carbides as a representative example of computational high-pressure studies. We predicted various compositions of Mg-C compounds up to 150 GPa and successfully reproduced previous experimental results. Interestingly, our proposed MgC2 at high pressure >7 GPa consists of extended carbon bonds, one-dimensional graphene layers, and Mg atomic layers, which provides a good platform to study superconductivity of metal intercalated graphene nano-ribbons. We found that this new phase of MgC2 could be recovered to ambient pressure and exhibited a strong electron-phonon coupling (EPC) strength of 0.6 whose corresponding superconductivity transition temperature reached 15 K. The EPC originated from the cooperation of the out-of-plane and the in-plane phonon modes. The geometry confinement and the hybridization between the Mg s and C p(z) orbitals significantly affect the coupling of phonon modes and electrons. These results show the importance of the high-pressure route to the synthesis of novel functional materials, which can promote the search for new phases of carbon-based superconductors.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/101085
- DOI
- 10.1038/s41598-019-56497-6
- ISSN
- 2045-2322
- Article Type
- Article
- Citation
- SCIENTIFIC REPORTS, vol. 9, 2019-12
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