Magnetic structure and anisotropy of fcc-iron nanoclusters trapped in carbon nanotube

Mossbauer spectroscopy combined with SQUID magnetometry was carried out in an applied magnetic field of up to 1 T at temperatures between 5 K and 300 K to investigate the atomic-level magnetic structure of the fcc-Fe nanoparticles. The corner Fe atoms in the fcc unit cell are in a high spin state, while the face-centered Fe atoms are in a low spin state when an interstitial carbon atom exists in the nearest neighbor, but the face-centered Fe have no moment without a nearest neighbor carbon.