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| 摘要: |
| 通过粒子群优化算法和密度泛函计算，证明了空间群为PMMA的正交晶系的碳同素异形体o-C8是稳定的超硬相. 声子谱计算表明，o-C8碳相是动力学稳定的；体积压缩计算表明，它是体模量为298.6 GPa的高度不可压缩材料. o-C8相是一种新型的密度为2.993 g/cm3、维氏硬度为67.0 GPa的低密度超硬材料. |
| 关键词: 碳，硬度，稳定性，结构 |
| DOI：10.1063/1674-0068/cjcp1809211 |
| 分类号: |
| 基金项目: |
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| o-C8 Carbon: a New Allotrope of Superhard Carbon |
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Jun-ru Kou,Ai-hua Cao,Song-li Liu,Li-hua Gan*
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| Abstract: |
| An orthonormal crystal of carbon with PMMA space group (o-C8) was found to be a stable superhard carbon allotrope by particle swarm optimization algorithm and density functional calculations. The phonon spectrum calculations demonstrate that the o-C8 carbon phase is dynamically stable. The volume compression calculations show that it is highly incompressible, with bulk modulus of 298.6 GPa. The calculations demonstrate that it is a low-density superhard material with density of 2.993 g/cm3 and Vickers hardness of 82.4 GPa. |
| Key words: Carbon, Hardness, Stability, Structures |