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

Paper NT+NS+EM+MS-ThA9
Improved Tungsten Disulfide Nanotubes as Tips for Scanning Probe Microscopy

Thursday, October 28, 1999, 4:40 pm, Room 6C

Session: Nanotubes: Functionalization and Metrology
Presenter: A. Rothschild, Weizmann Institute of Science, Israel
Authors: A. Rothschild, Weizmann Institute of Science, Israel
G. Frey, Weizmann Institute of Science, Israel
M. Homyonfer, Weizmann Institute of Science, Israel
M. Rappaport, Weizmann Institute of Science, Israel
S.R. Cohen, Weizmann Institute of Science, Israel
R. Tenne, Weizmann Institute of Science, Israel
Correspondent: Click to Email
Synthesis and applications of long and hollow WS@sub 2@ nanotubes are described. Although synthesis of nanotubes from various inorganic compounds have been reported, the high yields of uncontaminated nanotubes reported here represents a significant improvement over past efforts by ourselves and others.@footnote 1@,@footnote 2@ The nanotubes are synthesized in a two-step process the first being the creation of WO@sub 3@ nanoparticles by heating a tungsten filament in the controlled presence of water. The second step, sulfidization, resulted in a 30 times increase in the length of these particles without change in width so that nanotubes up to 10 microns in length and 20-40 nm width were formed. These tubes were attached to scanning force microscope (SFM) tips and used to image deep and sharp features inaccessible by sharp silicon tips. Due to their sandwich S-W-S structure, these nanotubes are probably stiffer than the carbon analogs and hence less prone to instabilities under such rigorous scanning conditions. We propose application of these probes for nanophotolithography, aided by the facile excitation of these compounds by visible and infra-red light. Support by the Israel Ministry of Science, Israel Science Foundation, and Applied Materials-Weizmann Foundation are gratefully acknowledged. A.R. is a recipient of the Lavoisier fellowship (France). @FootnoteText@ @footnote 1@ Y. Feldman, E. Wasserman, D.J. Srolovitz, R. Tenne, Science 267, 222 (1995). @footnote 2@ N.G. Chopra, et al, Science 269, 966 (1995).