Synthesis and magnetic study for Fe-doped carbon nanotubes (CNTs)

Synthesis and Magnetic Properties of Fe-incorporated Carbon Nanofibers by Ion-irradiation Method

“…3(a), typical coercivities (coercive fields) are Hc‖≈ 70 Oe and Hc ⊥ ≈ 75.3 Oe for the directions parallel (in-plane) and perpendicular to the substrate, respectively. Those values are larger than typical value for a bulk Fe at room temperature (e.g., around 0.9 Oe) [1,13] .…”

“…Thus, the synthesis and application of these metal-filled CNTs is an important and challenging research area. For the synthesis of CNTs incorporating metals and metal oxides, various kinds of techniques have been developed, including capillary action [4][5][6] , arc-discharge method [7][8][9] , wet chemical method [10,11] , catalyzed hydrocarbon [12] and pyrolyzing carbon-metal composites in Ar atmosphere [13] . However, in those conventional synthesis methods, the growth temperatures higher than 500 o C are generally required for the metal-filled CNT growth.…”

Deposition of iron nanoparticles onto multiwalled carbon nanotubes by helicon plasma-enhanced, chemical vapor deposition

“…5(c) shows that the coercivity of MWCNT/Fe nanoparticle hybrids decreases from 0.32 kOe at 5 K to 0.024 kOe at 300 K. We believe that the decrease of coercivity resulted from the depinning of domain walls in Fe nanoparticles with increasing temperature [21]. These results were in agreement with the previous report, where Fe-doped MWCNTs were formed by pyrolysis of ferrocene at 1050°C: [22] the Fe-doped MWCNTs were also ferromagnetic above 300 K, and showed temperature dependency of magnetization.…”

Synthesis and growth mechanism of metal filled carbon nanostructures by CVD using Ni/Y catalyst supported on copper

“…Yttria doped in nickel plays a significant role for the decomposition of the hydrocarbon by ensuring the formation of Ni nanoparticles through clagging the interaction between Ni and Cu. The distinguish from the previous reported metal filled CNTs is that some metal particles in one tube can be separated by graphitic layers and strings of onion-like carbon nanospheres are popular in the initial growth, which is hard to be explained by previous reported growth mechanisms [7][8][9]. So a sphere-tube growth mechanism mode of CNTs based on the experiments is proposed below.…”