Structural, mechanical, and electronic properties of P21/m-Carbon

• Published in: Chinese journal of physics (Taipei) 2020-10, Vol.67, p.63-68
• Main Authors: Ma, Jian-Li, Wu, Yi-Long, Fu, Zhi-Fen, Wei, Qun, Chen, Hai-Ping, Gao, Juan, Zhou, Jian-Ping, Liu, Peng
• Format: Article
• Language: English
• Subjects: Carbon; Electronic properties; First principle calculations; Mechanical properties
• ISSN: 0577-9073
• DOI: 10.1016/j.cjph.2019.12.014

•The structural, mechanical, and electronic properties of P21/m-carbon were investigated.•P21/m-carbon is an insulator with an indirect band gap of 3.83 eV.•The bulk moduli, shear moduli, and Vickers hardness values of P21/m-carbon are 398 GPa, 457 GPa, 82.3 GPa, respectively.•P21/m-carbon simultaneously possesses ultra-incompressible and the superhard property. The structural, mechanical, and electronic properties of P21/m-carbon were comprehensively investigated by using first principles calculations. Our calculated structure parameters are in good agreement with the previous theoretical values. P21/m-carbon consists of 10 atoms in a unit cell and is made of an exclusively sp3 hybridized bonding network. The calculated phonon spectra and elastic constant verify that P21/m-carbon is dynamically and mechanically stable at ambient pressure. The analysis of the electronic band structure reveals that P21/m-carbon is an insulator with a band gap of 5.47 eV. It has a large bulk moduli of 398 GPa and a high shear moduli of 457 GPa. Further mechanical properties demonstrate that P21/m-carbon is prone to be ductile and possesses a high Vickers hardness value of 82.3 GPa. These values show that P21/m-carbon simultaneously possesses ultra-incompressible and the superhard property. Furthermore, the X-ray diffraction spectra is also theoretically simulated to provide more structure information for future experimental observations.