Controlling the quantity of γ-Fe inside multiwall carbon nano-onions: the key role of sulfur

Abstract

One of the most interesting structural features of multiwall carbon onions (MWCNOs) and nanotubes (MWCNTs) is the excellent chemical stability, which allows in-situ encapsulation of chosen magnetic materials of interest...

Possible interplay of tangential and perpendicular modes in the growth of Fe-filled carbon nanotubes

“…4 HRTEM micrograph exhibiting the single-crystalline-like arrangement of an Fe 3 C nanowire encapsulated within a CNT, produced by pyrolysis of ferrocene/dichlorobenzene mixtures. 9 In the inset, FFT analyses evidence the single-crystalline nature of the Fe 3 C nanocrystal.…”

“…14 for a buckypaper film produced at low ferrocene concentrations. 9 Additional evaluation of the growth modes was then sought through analyses of the nanowire-catalyst regions located in proximity of the CNT-base, within the radial Fig. 12 Comparative plot showing the variation of the inner CNTcavity diameter as a function of the encapsulated nanowire diameter for a sample consisting of filled CNTs entangled into a buckypaper morphology (obtained by pyrolysis of ferrocene/dichlorobenzene mixtures at vapour flow rates of ∼20 ml min −1 ).…”

“…14 Comparative plot exhibiting the variation of the inner CNTcavity diameter as a function of the encapsulated nanowire diameter for a sample consisting of a filled CNTs entangled into a thin buckypaper morphology produced at low ferrocene concentration. 9 Fig. 15 TEM analyses of a CNT obtained by viscous-flow pyrolysis of ferrocene, exhibiting a fully encapsulated catalyst-nanowire on both ends (fully filled); see also ESI † Fig.…”

“…Owing to the chemical and physical properties which allow a complete protection from the external environment, CNTs have been also proposed as suitable nano-containers for encapsulation and stabilization of specific materials of interest. In particular, filling ironbased crystalline nanowires inside CNTs has rapidly become an important focus of research with potential applications in spintronics, 6 data storage devices, [7][8][9][10][11][12] nano-inductors, 13 microwave-absorption technology, [14][15][16] nano-thermometry, 17 nano-medicine, 17 contrast-agents 18 and others.…”

Chemical vapour synthesis of carbon nano-onions filled with high-spin ferromagnetic γ-Fe50Ni50 nanocrystals: a structural and magnetic investigation

“…The synthesis and manipulation of these structures has recently become of particular interest also for applications in hyperthermic dissipative systems, 13–21 where control of the Curie point T C would allow the self-regulation of chosen nanoscale magnetic particles and applications in magnetic hyperthermia cancer therapy. 15–19…”