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Abstract: Iron carbide Fe3C nanoparticles were fabricated by a chemical vapor condensation (CVC), and their structural and magnetic properties were investigated. It was found that the formation of iron carbide nanoparticles strongly depended on reaction temperature and pressure. The iron carbide was formed only above 650°C at 101kPa (760Torr) but never formed in vacuum (1.33Pa) regardless of reaction temperature. The fabricated iron carbide nanoparticles were spherical with T c of about 240°C. While the particles formed at 650°C (∼30nm) possessed a typical core–shell structure, those formed at 800°C (∼50nm) did not have such structure. The nanoparticles fabricated at 650°C and 800°C at 101kPa, exhibited M s of ∼125Am2/kg whereas i H c of the former was slightly higher (∼63kA/m) than that of the latter (∼40kA/m). [Copyright &y& Elsevier]

Nanosized titanium carbide particles were synthesized by the reaction of liquid magnesium and vaporized TiCl4+CxCl4 (x=1, 2) solution. Fine titanium carbide particles with about 50 nm were successfully produced by combining of Ti and C atoms released by chloride reduction of magnesium, and vacuum was then used to remove the residual phases of MgCl2 and excess Mg. With respect to the reaction kinetic, the activation energy for the reactions of TiCl4+C2Cl4 and Mg was found to 69 kJ mol-1, which was about half value against the use of TiCl4+CCl4, and such higher reactivity of the former contributed to increase the stoichiometry until the level of TiC0.96 and decrease the free carbon content below 0.3 wt.%. [Copyright &y& Elsevier]

Fe–Co nanoparticles were synthesized by the chemical vapor condensation process using the organometallics as precursors under a flowing helium atmosphere. The relations between the resulting microstructure, magnetic properties and the process parameters were investigated. The crystalline structure after oxidation at different temperatures was analyzed. The mean size of the Fe–Co nanoparticles increases with increasing the decomposition temperature. The saturation magnetization increases with increasing the particle size. The maximum value of the coercivity reaches up to 1739 Oe for the Fe–Co nanoparticles oxidized at 400 °C. [Copyright &y& Elsevier]

Magnetic Co nanoparticles were synthesized by a chemical vapor condensation method using the precursor of cobalt carbonyl as the source under a flowing inert gas atmosphere. Characteristics of the resulting material were investigated systematically by means of X-ray diffraction, high resolution transmission electron microscopy, TEM, X-ray photoelectron spectroscopy, vibrating sample magnetometer and differential thermal analysis-thermogravimetry. A correlation between the preparation conditions and the resulting microstructure of the nanoparticles was studied. [Copyright &y& Elsevier]

Iron–cobalt alloyed (Fe1−xCox, x≤50 wt.%) nanoparticles with core–shell structure was prepared by chemical vapor condensation (CVC) process and characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer. The particles having the mean size of 5–25 nm consisted of metallic cores and oxide shells. The nanoparticle size increased with increasing gas flow rate. The saturation magnetization and coercivity increased with increasing Co content, and the saturation magnetization reached its maximum rate at 40 wt.% Co. [Copyright &y& Elsevier]