First-principles study of structural, electronic, elastic, and thermal properties of Imm2-BC
Abstract
Using the first-principles method, we predict an orthorhombic boron-carbon binary structure with space group Imm2. This structure is verified to be dynamically and mechanically stable, and possesses a cavity of 27.5 Å2 that makes it a potential molecular sieve material. The C sp2 and sp3 hybridized bonding in Imm2 BC is an important factor for its structural stability. The energy band calculations reveal that Imm2 BC is a semiconductor with a band gap of 1.3 eV and has a promising application in the electro-optic field. The lattice thermal conductivity along the crystal [100] direction at room temperature is 186 W·m-1·K-1, that is about 5 times higher than those along the [010] and [001] directions, which stems from the different group velocity along the crystal direction. Moreover, the acoustic-optical coupling is important for heat transport in Imm2 BC, and the contribution of optical phonons to lattice thermal conductivity in the [100], [010], and [001] directions is 49%, 59%, and 61%, respectively. This study gives a fundamental understanding of the structural, electronic, elastic, and heat transport properties in Imm2 BC, further enriching the family of boron-carbon binary compounds.
- Publication:
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Chinese Physics B
- Pub Date:
- January 2019
- DOI:
- 10.1088/1674-1056/28/1/013101
- Bibcode:
- 2019ChPhB..28a3101L
- Keywords:
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- first principles;
- boron-carbon binary;
- electronic structure;
- thermal properties