摘要
层状氮掺杂石墨炔(NGDY)的成功合成(Nano Energy, 2018, 44, 144)引起了凝聚态物理和材料学领域科学家的广泛关注。在此,我们首先基于密度泛函理论计算确定了NGDY原子层的最佳堆垛次序,然后研究了其在双轴应变下的力学和电子性质。结果表明,NGDY能量最低的构型是ABC-堆垛结构。值得注意的是,在沿a、b方向的双轴应变下,该材料在c方向上表现出半拉胀行为。具体表现为:在双轴压缩应变下表现为普通材料的性质,即c方向晶格参数随双轴压缩应变增大而增大;在双轴拉伸应变下表现出拉胀材料的性质,即c方向晶格参数随双轴拉伸应变增大而增大。另外,在−0.05 ≤ ε ≤ 0.05的应变范围内,不管是拉伸应变还是压缩应变的增加均会导致体系带隙的增大。NGDY材料这种不同寻常的机械和电子性质表明其在新颖机械电子器件设计方面具有巨大潜力。
The successful synthesis of layered nitrogen-doped graphdiyne (NGDY) (Nano Energy, 2018, 44, 144) has attracted wide attention from scientists in condensed matter physics and materials. Firstly, we calculated the optimal stacking order of the NGDY atomic layer based on density functional theory, and then investigated its mechanical and electronic properties under biaxial strains. The results show that ABC-stacking structure has the lowest energy. It is worth noting that under biaxial strains along directions a and b, the material exhibits a half-auxetic behavior in direction c. Specifically, it shows the properties of ordinary materials under biaxial compression strains, that is, the lattice parameters in the c direction increase with the increase of biaxial compression strain. The lattice parameters in the c direction increase with the increase of the biaxial tensile strain. In addition, in the range of −0.05 ≤ ε ≤ 0.05, the increase of both tensile strain and compressive strain will lead to the increase of band gap. The unusual mechanical and electronic properties of NGDY material indicate that it has great potential in the design of electromechanical devices.
出处
《凝聚态物理学进展》
2023年第1期1-8,共8页
Advances in Condensed Matter Physics
