Xia Kang, Yu Xiaolong, Ding Chi, Lu Qing, Zhang Zhongwei, Sun Jian
College of Science, Nanjing Forestry University, Nanjing 210037, China.
National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Nano Lett. 2024 Sep 25;24(38):11865-11872. doi: 10.1021/acs.nanolett.4c02939. Epub 2024 Sep 12.
Intrinsic superconductivity is rarely discovered in -hybridized monolayer carbon allotropes. Here we design a carbon monolayer configured of pentagon, heptagon, and hexagon rings with plane group symmetry. Full- hybridization is proposed to favor thermal metastability on a low Gibbs free energy. The extremely small thermal expansion coefficient is predicted to the turn negative value to positive with elevating temperature. Carbon polygon structures remain intact at a high thermal temperature of 3,000 K. The high specific surface area is found to approach 2,700 m/g, with O-adsorption being advantageous over pristine graphene. We reveal electronic Fermi surfaces mediated by phonon modes of carbon out-of-plane vibrations. By calculating the Eliashberg equation, we evaluate intrinsic superconductivity with a large electron-phonon coupling coefficient. The superconducting transition temperature is estimated to reach 20 K under a high logarithmic average frequency. These first-principles calculations shall stimulate experimentalists' interest in exploring low-dimensional carbon superconductors with gas sensitivity.
本征超导性在sp³ 杂化的单层碳同素异形体中很少被发现。在此，我们设计了一种具有平面群对称性的由五边形、七边形和六边形环构成的碳单层。我们提出完全sp³ 杂化有利于在低吉布斯自由能下实现热亚稳性。预计极小的热膨胀系数会随着温度升高从负值变为正值。碳多边形结构在3000 K的高温下仍保持完整。发现其高比表面积接近2700 m²/g，氧吸附比原始石墨烯更具优势。我们揭示了由碳面外振动的声子模式介导的电子费米面。通过计算伊利亚申伯格方程，我们评估了具有大电子 - 声子耦合系数的本征超导性。在高对数平均频率下，超导转变温度估计达到20 K。这些第一性原理计算将激发实验人员对探索具有气体敏感性的低维碳超导体的兴趣。
