AVS 46th International Symposium
    Topical Conference on Emerging Opportunities and Issues in Nanotubes and Nanoelectronics Wednesday Sessions
       Session NT+NS+EM+MS-WeA

Paper NT+NS+EM+MS-WeA8
Carbon Nanotube Tips: Structures and Properties

Wednesday, October 27, 1999, 4:20 pm, Room 6C

Session: Nanotubes: Growth, Characterization and Properties I
Presenter: J. Han, NASA
Authors: J. Han, NASA
L. Yang, NASA
R.L. Jaffe, NASA
Correspondent: Click to Email
A variety of structures and properties of carbon nanotube tips present challenges in understanding of electron tunneling and field emission of carbon nanotube materials. Topologically, a nanotube tip can be formed by joining a tube bulk and a cone or a half the fullerene. Different configurations can be resulted from arrangement of topological defects. Energetically favorable configurations are identified and classified using functional theory and molecular mechanics calculations. They are further used for electronic structure calculations based on tight-binding approaches. The location and intensity of localizes states at tips are studied as functions of the size and configurations of tips. The differences in localized stated between one and four-orbital calculations are also compared. Experimental results of carbon nanotube field emission properties are related to the calculations of the localized stated of nanotube tips.