High temperature performance of coaxial h-BN/CNT wires above 1,000 °C: Thermionic electron emission and thermally activated conductivity

	High temperature performance of coaxial h-BN/CNT wires above 1,000 °C: Thermionic electron emission and thermally activated conductivity
	Yang Xinhe 1; Liu Peng 1; Zhou Duanliang 1; Gao Feng 2; Wang Xinhe 3; Lv Shiwei 1; Yuan Zi 1; Jin Xiang 1; Zhao Wei 1; Wei Haoming 1
刊名	Nano Research
	2019
卷号	12 期号:8 页码:1855-1861
关键词	high temperature wire carbon nanotube (CNT) h-boron nitride (h-BN) work function bandgap
ISSN号	1998-0124
英文摘要	The development of wires and cables that can tolerate extremely high temperatures will be very important for probing extreme environments, such as in solar exploration, fire disasters, high-temperature materials processing, aeronautics and astronautics. In this paper, a lightweight high-temperature coaxial h-boron nitride (BN)/carbon nanotube (CNT) wire is synthesized by the chemical vapor deposition (CVD) epitaxial growth of h-BN on CNT yarn. The epitaxially grown h-BN acts as both an insulating material and a jacket that protects against oxidation. It has been shown that the thermionic electron emission (1,200 K) and thermally activated conductivity (1,000 K) are two principal mechanisms for insulation failure of h-BN at high temperatures. The thermionic emission of h-BN can provide the work function of h-BN, which ranges from 4.22 to 4.61 eV in the temperature range of 1,306–1,787 K. The change in the resistivity of h-BN with temperature follows the ohmic conduction model of an insulator, and it can provide the “electron activation energy” (the energy from the Fermi level to the conduction band of h-BN), which ranges from 2.79 to 3.08 eV, corresponding to a band gap for h-BN ranging from 5.6 to 6.2 eV. However, since the leakage current is very small, both phenomena have no obvious influence on the signal transmission at the working temperature. This lightweight coaxial h-BN/CNT wire can tolerate 1,200 °C in air and can transmit electrical signals as normal. It is hoped that this lightweight high-temperature wire will open up new possibilities for a wide range of applications in extreme high-temperature conditions.
语种	英语
CSCD记录号	CSCD:6619257
内容类型	期刊论文
源URL	[http://ir.yic.ac.cn/handle/133337/34979]
专题	中国科学院烟台海岸带研究所
作者单位	1.清华大学 2.中国科学院烟台海岸带研究所 3.北京航空航天大学
推荐引用方式 GB/T 7714	Yang Xinhe,Liu Peng,Zhou Duanliang,et al. High temperature performance of coaxial h-BN/CNT wires above 1,000 °C: Thermionic electron emission and thermally activated conductivity[J]. Nano Research,2019,12(8):1855-1861.
APA	Yang Xinhe.,Liu Peng.,Zhou Duanliang.,Gao Feng.,Wang Xinhe.,...&Jiang Kaili.(2019).High temperature performance of coaxial h-BN/CNT wires above 1,000 °C: Thermionic electron emission and thermally activated conductivity.Nano Research,12(8),1855-1861.
MLA	Yang Xinhe,et al."High temperature performance of coaxial h-BN/CNT wires above 1,000 °C: Thermionic electron emission and thermally activated conductivity".Nano Research 12.8(2019):1855-1861.