Iron carbide nanoparticles produced by laser ablation in organic solvent

Laser ablation of iron in an organic solvent (pentane, hexane, or decane) was performed using an air-tight cell to produce iron carbide nanoparticles. Mossbauer spectra of the nanoparticles were obtained at room temperature. They revealed that the nanoparticles consisted of two paramagnetic components and magnetic components. The two paramagnetic components were a high-spin Fe(II) species and an amorphous iron carbide containing a large amount of carbon. Whereas the magnetic components measured at room temperature exhibited superparamagnetism, those measured at low temperature were fitted by a combination of four sextets, which were assigned to Fe7 C 3. The Fe7 C 3 yield was higher in higher molecular weight solvents. Transmission electron microscopy (TEM) images of the samples showed that the nanoparticles were spherical with diameters in the range 10–100 nm.