论文标题
具有高能量密度和机械强度的新2D辅助CN2纳米结构
A new 2D auxetic CN2 nanostructure with high energy density and mechanical strength
论文作者
论文摘要
使用AB-Initio分子动力学（AIMD）和密度官能理论计算预测了新的二维CN2结构的存在。它包括四方和六角形环，其与屈曲平面上的C-N和N-N键组成，等于Tetrahex-碳副同质量。它是热力学和动力学稳定的，由其声子频谱和AIMD提出。该纳米片具有高浓度的N，并包含N-N单键，能量密度为6.3 kJ/g，表明潜在的应用是高能量密度材料。它具有泊松比为负的外来机械性能和各向异性的杨氏模量。锯齿形方向的模量预计为340 N/m，比H-BN和Penta-CN2板更硬，与石墨烯相当。它的理想强度为28.8 N/m，胜过五角形的优势。该材料在将高达10％（13％）的单轴菌株（扶手椅）方向或双轴应变施加到最高5％的单轴应变时保持了声子稳定性。它具有4.57 eV的宽间接HSE带隙，通过应变在3.37-4.57 eV之间可调节。还探索了双层结构。这种独特的特性可能在高能密度材料，纳米力学和电子产品中具有潜在的应用。
The existence of a new two dimensional CN2 structure was predicted using ab-initio molecular dynamics (AIMD) and density-functional theory calculations. It consists tetragonal and hexagonal rings with C-N and N-N bonds arranged in a buckling plane, isostructural to tetrahex-carbon allotrope. It is thermodynamically and kinetically stable suggested by its phonon spectrum and AIMD. This nanosheet has high concentration of N and contains N-N single bonds with an energy density of 6.3 kJ/g, indicating potential applications as high energy density materials. It possesses exotic mechanical properties with negative Poisson's ratio and an anisotropic Young's modulus. The modulus in the zigzag direction is predicted to be 340 N/m, stiffer than h-BN and penta-CN2 sheets and comparable to graphene. Its ideal strength of 28.8 N/m outperforms that of penta-graphene. The material maintains phonon stability upon the application of uniaxial strain up to 10% (13%) in the zigzag (armchair) direction or biaxial strain up to 5%. It possesses a wide indirect HSE band gap of 4.57 eV which is tunable between 3.37 - 4.57 eV through strain. Double-layer structures are also explored. Such unique properties may have potential applications in high energy density materials, nanomechanics and electronics.
