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Potential Semiconducting and Superconducting Metastable Si3C Structures under Pressure

MetadataDetails
Publication Date2017-12-14
JournalChemistry of Materials
AuthorsGuoying Gao, Xiaowei Liang, N. W. Ashcroft, Roald Hoffmann
InstitutionsCornell University, Yanshan University
Citations6

Si3C is predicted to take on a diamond type structure (space group: I4̅2d), at P = 1 atm, consistent with the experimental results on a cubic Si0.75C0.25 alloy. This structure is computed to be a semiconductor with a direct band gap of about 1.3 eV, within the desired values. Under pressure, Si3C may transform to metastable metallic R3̅m-2 and R3̅m-3 structures at about 25 and 250 GPa, respectively. Both are layered structures with six-coordinate Si and unusual six-coordinate carbon atoms. The R3̅m-1 and R3̅m-2 structures are both estimated to be superconductors with Tc of a few Kelvin. This is the first time that superconductivity in undoped silicon carbides is calculated.

  1. 1998 - SiC materials and devices