中国物理B ›› 2019, Vol. 28 ›› Issue (6): 66301-066301.doi: 10.1088/1674-1056/28/6/066301

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Theoretical analysis of cross-plane lattice thermal conduction in graphite

Yun-Feng Gu(顾云风)   

  1. College of Electronic and Mechanical Engineering, Nanjing Forestry University, Nanjing 210037, China
  • 收稿日期:2019-03-07 修回日期:2019-03-27 出版日期:2019-06-05 发布日期:2019-06-05
  • 通讯作者: Yun-Feng Gu E-mail:gu_yunfeng@sina.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 51376094) and Jiangsu Overseas Visiting Scholar Program for University Prominent Young & Middle-aged Teachers and Presidents.

Theoretical analysis of cross-plane lattice thermal conduction in graphite

Yun-Feng Gu(顾云风)   

  1. College of Electronic and Mechanical Engineering, Nanjing Forestry University, Nanjing 210037, China
  • Received:2019-03-07 Revised:2019-03-27 Online:2019-06-05 Published:2019-06-05
  • Contact: Yun-Feng Gu E-mail:gu_yunfeng@sina.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 51376094) and Jiangsu Overseas Visiting Scholar Program for University Prominent Young & Middle-aged Teachers and Presidents.

摘要:

A theoretical analysis of the cross-plane lattice thermal conduction in graphite is performed by using first-principles calculations and in the single-mode relaxation time approximation. The out-of-plane phonon acoustic mode ZA and optical mode ZO' have almost 80% and 20% of contributions to cross-plane heat transfer, respectively. However, these two branches have a small part of total specific heat above 300 K. Phonons in the central 16% of Brillouin zone contribute 80% of cross-plane transport. If the group velocity angle with respect to the graphite layer normal is less than 30circ, then the contribution is 50% at 300 K. The ZA phonons with long cross-plane mean free path are focused in the cross-plane direction, and the largest mean free path is on the order of several micrometers at room temperature. The average value of cross-plane mean free path at 300 K is 112 nm for ZA phonons with group velocity angle with respect to the layer normal being less than 15circ. The average value is dropped to 15 nm when phonons of all branches in the whole Brillouin zone are taken into account, which happens because most phonons have small or even no contributions.

关键词: graphite, cross-plane thermal conduction, phonon mean free path, layered systems

Abstract:

A theoretical analysis of the cross-plane lattice thermal conduction in graphite is performed by using first-principles calculations and in the single-mode relaxation time approximation. The out-of-plane phonon acoustic mode ZA and optical mode ZO' have almost 80% and 20% of contributions to cross-plane heat transfer, respectively. However, these two branches have a small part of total specific heat above 300 K. Phonons in the central 16% of Brillouin zone contribute 80% of cross-plane transport. If the group velocity angle with respect to the graphite layer normal is less than 30circ, then the contribution is 50% at 300 K. The ZA phonons with long cross-plane mean free path are focused in the cross-plane direction, and the largest mean free path is on the order of several micrometers at room temperature. The average value of cross-plane mean free path at 300 K is 112 nm for ZA phonons with group velocity angle with respect to the layer normal being less than 15circ. The average value is dropped to 15 nm when phonons of all branches in the whole Brillouin zone are taken into account, which happens because most phonons have small or even no contributions.

Key words: graphite, cross-plane thermal conduction, phonon mean free path, layered systems

中图分类号:  (Phonon states and bands, normal modes, and phonon dispersion)

  • 63.20.D-
63.22.Np (Layered systems) 65.40.-b (Thermal properties of crystalline solids)