Soft magnetic performance improvement of Fe-filled carbon nanotubes by water-assisted pyrolysis route

We prepared alpha-Fe filled carbon nanotubes (CNTs) by introduction of appropriate water vapours during the growth process and found that the walls of carbon nanotubes are reduced effectively. It is also found that soft magnetic performances of Fe-filled CNTs (Fe@CNTs) are improved remarkably compared with that without water assistance. When the flow of water was 0.04 mL/min, the saturation magnetization (M) value of Fe@CNTs reaches to 112.40 emu/g, which is about 3 times as high as that without water assistance. While the coercivity (H-c) value is 97.01 Oe, which is reduced to about 1/4 of that. These are favourable to their applications in magnetic fluid and electromagnetic wave absorbing in the future. (c) 2007 WILEYNCH Verlag GmbH & Co. KGaA, Weinheim.