...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Mechanochemical formation of heterogeneous diamond structures during rapid uniaxial compression in graphite
【24h】

Mechanochemical formation of heterogeneous diamond structures during rapid uniaxial compression in graphite

机译：石墨中快速单轴压缩过程中异质金刚石结构的机械化学形成

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We predict mechanochemical formation of heterogeneous diamond structures from rapid uniaxial compression in graphite using quantum molecular dynamics simulations. Ensembles of simulations reveal the formation of different diamondlike products starting from thermal graphite crystal configurations. We identify distinct classes of final products with characteristic probabilities of formation, stress states, and electrical properties and show through simulations of rapid quenching that these products are nominally stable and can be recovered at room temperature and pressure. Some of the diamond products exhibit significant disorder and partial closure of the energy gap between the highest-occupied and lowest-unoccupied molecular orbitals (i.e., the HOMO-LUMO gap). Seeding atomic vacancies in graphite significantly biases toward forming products with small HOMO-LUMO gap. We show that a strong correlation between the HOMO-LUMO gap and disorder in tetrahedral bonding configurations informs which kinds of structural defects are associated with gap closure. The rapid diffusionless transformation of graphite is found to lock vacancy defects into the final diamond structure, resulting in configurations that prevent sp~3 bonding and lead to localized HOMO and LUMO states with a small gap.
机译：我们使用量子分子动力学模拟从石墨中的快速单轴压缩预测了异质金刚石结构的机械化学形成。模拟结果表明，从热石墨晶体结构开始，形成了不同的类金刚石产品。我们确定了最终产品的不同类别，这些产品具有形成，应力状态和电性能的特征概率，并通过快速淬火的模拟表明这些产品名义上稳定并且可以在室温和压力下回收。一些钻石产品表现出明显的无序性，并且在最高占有和最低未占有分子轨道之间的能隙（即HOMO-LUMO间隙）部分闭合。石墨中的晶种原子空位明显偏向于形成具有较小HOMO-LUMO间隙的产物。我们表明，HOMO-LUMO间隙与四面体键合结构中的无序之间有很强的相关性，表明哪些类型的结构缺陷与间隙闭合有关。发现石墨的快速无扩散转变将空位缺陷锁定在最终的金刚石结构中，从而导致了防止sp〜3键结合并导致局部HOMO和LUMO状态（具有较小间隙）的结构。

著录项

  • 来源
    《Physical review》 |2018年第18期|184106.1-184106.9|共9页
  • 作者

    Malthew P. Kroonblawd; Nir Goldman;

  • 作者单位

    Physical and Life Sciences Directorate, Lawrence Livennore National Laboratory, Livennore, California 94550, United Stales;

    Physical and Life Sciences Directorate, Lawrence Livennore National Laboratory, Livennore, California 94550, United Stales;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号