Wang Shuaiwei, Shi Bingjun
Henan Key Laboratory of Nanocomposites and Applications, Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou 450006, China.
Henan Key Laboratory of Photovoltaic Materials, Henan University, Kaifeng 475004, China.
Phys Chem Chem Phys. 2022 Sep 21;24(36):21806-21811. doi: 10.1039/d2cp01469f.
Auxetic and semimetallic materials possess many advanced applications due to the negative Poisson's ratio (NPR) effect and unique electronic properties. However, candidates with the above properties are rather scarce, especially in the 2D carbon materials. Here, a new 2D NPR material with a Dirac nodal ring, named ographene, is identified using first-principles calculations. Ographene possesses anisotropic Young's modulus and unusual in-plane NPR (-0.11), which mainly originated from its puckered tetrahedron structure. In addition, the electronic band structure calculations show that ographene is a topological node-ring semimetal with high Fermi velocity. Moreover, the electronic band structure is robust against external strain. The intrinsic NPR coupled with robust electronic properties renders auxetic ographene promising for applications in electronics and mechanics areas.
由于负泊松比（NPR）效应和独特的电子特性，拉胀和半金属材料具有许多先进的应用。然而，具有上述特性的材料相当稀少，尤其是在二维碳材料中。在此，通过第一性原理计算确定了一种具有狄拉克节环的新型二维NPR材料——卵形石墨烯。卵形石墨烯具有各向异性的杨氏模量和异常的面内NPR（-0.11），这主要源于其褶皱的四面体结构。此外，电子能带结构计算表明，卵形石墨烯是一种具有高费米速度的拓扑节环半金属。而且，其电子能带结构对外加应变具有鲁棒性。固有的NPR与稳健的电子特性相结合，使得拉胀性的卵形石墨烯在电子学和力学领域具有广阔的应用前景。
