Transport in Single-Walled Carbon Nanotube Coatings of Silica Fibers
Nikesh Koirala and Pradeep Subedi, St. John’s University Student
Robin Helburn, Department of Chemistry, Pace University
Qi Lu and Vladimir Samuilov, Department of Physics, St. John’s College of Liberal Arts and Sciences
Abstract: Since their discovery, carbon nanotubes have triggered myriads of studies owing to their unique mechanical and electronic properties. Herein, we describe a novel approach to the assembly of SWCNT-based system and its properties in electric transport and magnetotransport. The dense coating of SWCNTs on silica fiber was assembled through the creation of hydrocarbon chains on the surface of silica fiber by the silanization method. The SWCNTs, either acid oxidized or pristine, were dispersed in water by sonication and then self-assembled to form a coating on the surface of silanized silica fiber when it is in presence. The coating is annealed by oven heating at T= 250 o C.The SWCNTs assembled on the surface of the silica fibers have shown low resistance (~10 k W at room temperature) and weak dependence of the resistance on temperature (5 times increasing in the temperature range 1.6-300 K). The resistance dependence on temperature can be described by the following dependence in a wide temperature range
The magnetoresistance measurements were conducted in the fields up to 8 T. The magnetoresistance was found to be positive at low temperatures 1.6-4K and negative at higher temperatures. A possible mechanism of electronic transport in the arrays of multi-wall carbon nanotubes is discussed.