Field Emission Patterns Originating from Pentagons at the Tip of a Carbon Nanotube

Abstract

Field emission of electrons from multiwall carbon nanotubes (MWCNTs) has been investigated in ultra-high vacuum by field emission microscopy (FEM). MWCNTs whose tips are capped by curved graphite layers give FEM patterns consisting of 6 bright pentagons, each of which has a dark region in its center. Interference fringes are also observed between adjacent pentagonal rings. The present result shows a direct evidence of the presence of 6 pentagons on a tip of a closed carbon nanotube.