• 文献标题:   Phonons, Localization, and Thermal Conductivity of Diamond Nanothreads and Amorphous Graphene
  • 文献类型:   Article
  • 作  者:   ZHU TS, ERTEKIN E
  • 作者关键词:   phonon, vibrational energy transport, disorder, graphene, diamond nanothread
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Illinois
  • 被引频次:   85
  • DOI:   10.1021/acs.nanolett.6b00557
  • 出版年:   2016

▎ 摘  要

Recently, the domains of low-dimensional (low-D) materials and disordered materials have been brought together by the demonstration of several new low-D, disordered systems. The thermal transport properties of these systems are not well-understood. Using amorphous graphene and glassy diamond nanothreads as prototype systems, we establish how structural disorder affects vibrational energy transport in low-dimensional, but disordered, materials. Modal localization analysis, molecular dynamics simulations, and a generalized model together demonstrate that the thermal transport properties of these materials exhibit both similarities and differences from disordered 3D materials. In analogy with 3D, the low-D disordered systems exhibit both propagating and diffusive-vibrational modes. In contrast to 3D, however, the diffuson contribution to thermal transport in these low-D systems is shown to be negligible, which may be a result of inherent differences in the nature of random walks in lower dimensions. Despite the lack of diffusons, the suppression of thermal conductivity due to disorder in low-D systems is shown to be mild or comparable to 3D. The mild suppression originates from the presence of low frequency vibrational modes that maintain a well-defined polarization and help preserve the thermal conductivity in the presence of disorder.