We have synthesized multiwalled carbon nanotubes (MWNTs) including Fe catalysts by the vapor phase growth method at 950°C. Different Fe concentrations were obtained by varying the Ar and CO flow rates during the vapor phase growing of the MWNTs. Magnetic properties of the MWNTs with different Fe concentrations were characterized by means of SQUID measurements in the temperature range of 5-300 K. As a result, superparamagnetic behaviors were observed at all the Fe concentrations. The form of the Fe catalysts included in MWNTs was discussed in view of the change of the average magnetic moment and the number of Fe particles with changing Fe concentration.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics