skip to main content

Title: Effect of hydrogen plasma irradiation of catalyst films on growth of carbon nanotubes filled with iron nanowires

Carbon nanotubes filled with iron (Fe-filled CNTs) show shape anisotropy on account of the high aspect ratio of magnetic nanowires, and are promising candidates for various applications, such as magnetic recording media, probes for scanning force microscopy, and medical treatment for cancer. The ability to appropriately control the magnetic properties of CNTs for those applications is desirable. In this study, the authors investigated magnetic properties of Fe-filled CNTs synthesized by thermal chemical vapor deposition for the purpose of tuning their coercivity. Here, the authors implemented hydrogen plasma irradiation of catalyst film that was previously deposited on a substrate as a catalyst layer. This treatment activates the catalyst film and thus enhances the growth of the Fe-filled CNTs. It was confirmed that the H{sub 2} plasma irradiation enhances the growth of the CNTs in terms of increasing their length and diameter compared to CNTs without irradiation. On the other hand, the coercivity of Fe-filled CNTs dropped to approximately half of those without H{sub 2} plasma irradiation. This is probably due to a decrease in the aspect ratio of the Fe nanowires, which results from the increase in their diameter. Furthermore, the crystal structure of the Fe nanowires may affect the coercivity.
Authors:
; ; ;  [1]
  1. Graduate School of Engineering, Mie University, 1577 Kurima-machiya-cho, Tsu 514-8507 (Japan)
Publication Date:
OSTI Identifier:
22258786
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 32; Journal Issue: 2; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ASPECT RATIO; CARBON NANOTUBES; CATALYSTS; CHEMICAL VAPOR DEPOSITION; COERCIVE FORCE; COMPARATIVE EVALUATIONS; CRYSTAL STRUCTURE; FILMS; HYDROGEN; IRON; IRRADIATION; MAGNETIC PROPERTIES; NEOPLASMS; PLASMA; QUANTUM WIRES; SUBSTRATES; WIRES