Magnetic Carbon Nanotubes: Materials Development and Property Characterization

A versatile chemical method was used to fill multi-wall carbon nanotubes (MWCNTs) with ferromagnetic nanoparticles [1]. For the first time, pulsed laser deposition and magnetron DC sputtering were used to fill vertically aligned MWCNTs. The later approaches gave high-yield nanoparticle filling of MWCNTs. Samples were characterized by Electron Microscopy, Energy Dispersive Spectroscopy, M\"{o}ssbauer Spectroscopy, and magnetization measurements. M\"{o}ssbauer measurements on chemically impregnated MWCNTs clearly show the presence of atomic Fe as well as mixed phases of Fe nano-particles inside the tubes. Magnetization measurements on PLD-filled vertically aligned MWCNTs indicate reasonable coercivity. However, the magnetic anisotropy appears to be randomly oriented, suggesting polycrystalline sample. \newline Acknowledgement: The research at Morgan State University was partially supported by the US ARL-WMRD (W1813LT-5006-7056). \newline [1] D. Seifu, Y. Hijji, G. Hirsch, and S. P. Karna, \textit{J. Magn. Magn. Mat.} \textbf{320}, 312 (2008).