Sulfidized Fe-C nanocomposite powders produced by one-step laser pyrolysis technique

Laser pyrolysis was employed to synthesize iron-based magnetic nanocomposites from fixed Fe(CO)(5) and various CS2 vapor flows by using C2H4 as sensitizer. The resulted nanopowders were composed from a mixture of iron-containing phases: metallic, carbides, oxide (maghemite) and sulfide (pyrrhotite). The gamma Fe2O3 was formed after post-synthesis air exposure, the highest oxygen content being found in the powder obtained from the lowest CS2 flow. TEM images reveal aggregates of core-shell nanoparticles (7-25 nm in size) for the sample with the highest sulfur content, whereas chained particles (15-30 nm) with empty core/porous shell morphology was observed for those with the lowest sulfur content.