Open AccessField evaporation of the end of a carbon nanotube
Author(s) -
Bai Xin,
Mingsheng Wang,
Linjun Yang,
Gengmin Zhang,
Zhaoxiang Zhang,
Xingyu Zhao,
Guo Deng-Zhu,
Zheng Xue
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.4596
Subject(s) - field electron emission , sublimation (psychology) , materials science , evaporation , carbon nanotube , field (mathematics) , dangling bond , electric field , work function , nanotube , field desorption , field ion microscope , field emission microscopy , desorption , nanotechnology , atomic physics , analytical chemistry (journal) , ion , thermodynamics , physics , chemistry , electron , optics , ionization , optoelectronics , adsorption , silicon , mathematics , psychotherapist , psychology , layer (electronics) , quantum mechanics , chromatography , pure mathematics , diffraction
A single multi-walled carbon nanotube (MWCNT)was assembled onto a W tip and transferred to an ultrahigh vacuum field-emission/field-ion microscope (UHV-FEM/FIM)for the study of field evaporation and field emission. The results showed that the field evaporation lowered the work function of the MWCNT and thus enhanced its field emission. The evaporation field of the MWCNT was estimated to be lower than 1.3×108V·cm-1 and the evaporation rate under this field was measured to be 9.4nm·min-1. The physical origin of the fact that the evaporation field of the MWCNT was much lower than the theoretical value for carbon is also qualitatively explained. Firstlythe clean end of the MWCNTwhich resulted from field desorptioncontained a large number of dangling bonds and the C atoms on it had small coordination numberthus the heat of sublimation of these C atoms was low. SecondlyH atoms that possibly existed in the MWCNT could collide with the C atoms under strong electric field and make the latter evaporate easier. These results indicated an effective approach to obtaining better field emission performance of a carbon nanotube by cutting it short using field evaporation.