Fig. 2
a Low-magnification TEM image of Fe nanoparticle arrays deposited on a TEM grid covered by amorphous carbon film, with a deposition rate of 0.1 Å s−1. Domains of close-packed 2D monolayers with long orders can be identified. b High-magnification TEM image of an ordered densely packed 2D superlattice of Fe nanoparticles. c FFT corresponding to nanoparticle arrays in (a). d HTREM image shows lattice images of individual Fe nanoparticles