Magnetic characterization of iron nanocubes

Nearly perfect single crystalline Fe core-shell nanocubes with (100) facets and 13.6 nm edge length were prepared by wet-chemical methods. While the core is metallic, the shell is composed of either Fe 3 O 4 or γ -Fe 2 O 3 . The cubes were deposited onto GaAs substrates with monolayer coverage as proved by scanning electron microscopy. Oxygen and hydrogen plasmas were used to remove the ligand system and the oxide shell. Both types of samples were investigated by ferromagnetic resonance. While the g -factor ( g = 2.09 ) and crystalline anisotropy ( K 4 = 4.8 × 10 4 J / m 3 ) of the pure iron cubes show up with bulk values, the saturation magnetization is reduced to ( M ( 5 K ) = ( 1.2 ± 0.12 ) × 10 6 A / m ) 70% of bulk value and the effective damping parameter ( α = 0.03 ) is increased by one order of magnitude with respect to bulk Fe.