Nucleation and growth model for {110}- and {111}-truncated nanoparticles

Nanoparticle-sized powders have seen more and more use in many of today’s applications. As particle size decreases, many properties change including the ability to embed the small particles in liquids and other media. With decreasing size, however, surface energy becomes more important and can dictate the final shape of the particle. In applications based on polar molecules attaching to the nanoparticle surface, the surface morphology can become a key design parameter. A nucleation and growth model has been constructed for truncated body-centered cubic derivative materials, along with an update to previously published work on face-centered cubic materials. The model shows that for (110)- and (111)-truncations of a cube with a specified surface energy for each surface, the critical nuclei and equilibrium growth shapes are the same, supporting the theory of self-similar growth that had only been mentioned previously, but never proven. In this analysis, saddle points play an important role in determining the critical nuclei for comparison with the equilibrium growth shapes.