Size Effect on Crystal Morphology of Faceted Face-Centered Cubic Fe Nanoparticles

Faceted metal nanoparticles have attracted much attention owing to their size and shape enhanced unique physical and chemical properties. Here we successfully synthesized face-centered cubic (fcc) Fe nanoparticles with diverse morphologies including icosahedron, decahedron, 5-fold twinned nanorod, tetrahedron and cube. A size effect on the particle morphologies of these faceted fcc-Fe nanoparticles was revealed. Small sizes (5-13 nm) favor icosahedral nanoparticles; decahedron and 5-fold twinned nanorods are favored at intermediate sizes (12-164 nm), and triangular plate and cube at large sizes such as 200 nm. This size-morphology dependence correlation of faceted fcc-Fe nanoparticles can be well explained by thermodynamic calculations.