Author/Authors :
Luca Camilli، نويسنده , , Manuela Scarselli، نويسنده , , Silvano Del Gobbo، نويسنده , , Paola Castrucci، نويسنده , , Francesca Romana Lamastra، نويسنده , , Francesca Nanni، نويسنده , , Eric Gautron، نويسنده , , Serge Lefrant
، نويسنده , , Franco D’Orazio، نويسنده , , Franco Lucari، نويسنده , , Maurizio De Crescenzi، نويسنده ,
Abstract :
Multiwalled carbon nanotubes synthesized directly on austenitic stainless steel result in being filled with pure iron nanoparticles. X-ray diffraction shows that the nanoparticles are either in the γ- or α-phase, although iron in the original alloy is in γ-phase because of the presence of nickel. This phase transformation is due to the selective extraction of iron, performed by carbon nanotubes during their growth. A high coercivity of iron-filled carbon nanotubes is measured although the starting steel is paramagnetic. The presence of the α-phase, the magnetic anisotropy and the single domain character of the Fe nanoparticles explain their magnetic behavior.
