Multi-Walled Carbon Nanotubes without and with Metal Filling

Abstract

Electron microscope studies are reported of MWCNTs without and with metallic encapsulations prepared by pyrolysis of organo-metallic precursors such as iron(II)phthalocyanine and ferrocene/anthracene mixtures. For straight and well-ordered MWCNTs, we obtained clear evidence of a scroll type structure with uniform chirality. Conical growth implicated the opening of the tube walls by termination of the graphene layers at the wall surfaces. Evidence is provided of the participation of iron carbide as an intermediate phase during graphite formation. Coercivities of the nanowire material up to 2550 Oe at 5 K, and constant saturation magnetization were measured.