Structural characteristics of Fe3C-based nanomaterials prepared by laser pyrolysis from different gas-phase precursors

Alexandrescu, R.; Morjan, I.; Dumitrache, F.; Bı̂rjega, R.; Jaeger, Christian; Mutschke, H.; Soare, I.; Gavrila-Florescu, L.; Ciupină, V.

doi:10.1016/j.msec.2006.07.008

Cited by 8 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cementite (Fe 3 C) has been reported on the nanoscale, but mainly synthesized via laser pyrolysis and other high-temperature methods. , As will be shown below, we have synthesized nanoparticles with a cementite core, which yields their dominant ferromagnetic behavior. These nanoparticles also exhibit a much weaker superparamagnetic response associated with antiferromagnetic coupling in an oxide shell surrounding the cementite, which is strongly dependent on temperature because of the existence of fluctuations of the relative orientation of the surface moments with respect to their own anisotropy axis.…”

Section: Introductionmentioning

confidence: 99%

Gold-Coated Cementite Nanoparticles: An Oxidation-Resistant Alternative to α-Iron

et al. 2009

View full text Add to dashboard Cite

Iron-based nanoparticles are desirable for many applications because of their magnetic properties and inherent biocompatibility. Metallic iron, or R-Fe, is the most sought after because of its high saturation magnetization (up to 220 emu/g). This magnetization in iron nanoparticles is difficult to reach or maintain because of the ease of oxidation, which greatly reduces the magnetization values (90 emu/g or less). Here, we report the synthesis of an iron-based nanoparticle comprising a magnetic cementite core (Fe 3 C) that is more oxidation-resistant than R-Fe, an oxide layer, and a gold coating for passivation and easy functionalization. The nanoparticle structure was confirmed via X-ray absorption fine structure and M€ ossbauer experiments, and morphology was confirmed using transmission electron microscopy. Magnetic characterization yielded a saturation magnetization of 110 emu/g, thus demonstrating cementite as more stable alternative to R-Fe with higher magnetic moments than the iron oxides.

show abstract

Section: Introductionmentioning

confidence: 99%

Gold-Coated Cementite Nanoparticles: An Oxidation-Resistant Alternative to α-Iron

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Natural logarithm of the maximum oxidation degree at a given temperature vs. reciprocal temperature for the oxidized (solid line) and passivated (dash line) samples ods for their production e.g. conventional 20 -23 and modified arc -discharge 24,25 , laser pyrolysis 26 . But one of the most simple and inexpensive method is Chemical Vapour Deposition.…”

Section: Catalyst For Carbon Nanomaterials Formationmentioning

confidence: 99%

The possibility of implementation of spent iron catalyst for ammonia synthesis

Ekiert

Pelka

Lubkowski

et al. 2009

Polish Journal of Chemical Technology

View full text Add to dashboard Cite

show abstract

“…The common Fe 3 C is orthorhombic, actually, it also has hexagonal crystalline structure. Presently, the synthesis of Fe 3 C powder or particles is mainly involved in mechanical alloying by high-energy ball milling [2][3][4][5] and laser pyrolysis of Fe(CO) 5 -based gas mixtures [6], and the preparation methods of bulk Fe 3 C includes hot isostatic pressing or hot extrusion followed by uniaxial pressing [7] and spark plasma sintering combined with mechanical alloying [8,9]. Similarly, the mechanical alloying process can also fabricate Fe-Fe 3 C composite powder [10].…”

Section: Introductionmentioning

confidence: 99%

Preparation Technology and Mechanical Properties of Fe-C Composites Fabricated by Plasma Activated Sintering

Liu

Zhou

Zhao

et al. 2013

AMM

View full text Add to dashboard Cite

The Fe-C composites were fabricated by a combination of high-energy ball milling of Fe-C powder mixtures and plasma activated sintering process. An orthogonal experiment in four factors (including original powder composition, sintering temperature, applied pressure and holding time) and three levels was employed to investigate the effects of preparation technology on mechanical properties (bending strength and hardness) of the Fe-C composite. The experimental results show that the crystalline Fe3C phase can be produced by the rapid sintering process, though it is cannot form theoretically due to the high Gibbs free energy, and more or less holes and composition segregation phenomenon coexist in the composite. The original powder composition plays the leading role in both the mechanical properties of the Fe-C composites. However, the effects of the other parameters on the bending strength and hardness of the composite are somewhat different. The optimal technology combinations for the bending strength and hardness are obtained as follows: 50Fe+50Fe3C/1373 K/400 s/20 MPa and 50Fe+50Fe3C/50 MPa/1273 K/400 s, respectively.

show abstract

Structural characteristics of Fe3C-based nanomaterials prepared by laser pyrolysis from different gas-phase precursors

Cited by 8 publications

References 11 publications

Gold-Coated Cementite Nanoparticles: An Oxidation-Resistant Alternative to α-Iron

Gold-Coated Cementite Nanoparticles: An Oxidation-Resistant Alternative to α-Iron

The possibility of implementation of spent iron catalyst for ammonia synthesis

Preparation Technology and Mechanical Properties of Fe-C Composites Fabricated by Plasma Activated Sintering

Contact Info

Product

Resources

About