Magnetic properties of cementite (Fe3C) nanoparticle agglomerates in a carbon matrix.

Magnetic properties of two FeC samples with different amounts of carbon have been studied. In both cases, the amount of carbon was well above the mass sufficient to transform nanocrystalline iron into iron carbide (cementite). Through the dc magnetic and transmission electron microscopy (TEM) measurements it was shown that cementite nanoparticles formed agglomerates; the size distribution of these nanoparticles was very wide, and superparamagnetic-like behaviour was not observed even at room temperature. [ABSTRACT FROM AUTHOR]