Understanding the Growth Mechanisms of Quantum Size Effect Nanocrystals Paul F. Miceli, Department of Physics and Astronomy, University of Missouri-Columbia The small size of Pb nanocrystals leads to novel and unexpected behavior exhibits particular “magic” crystal heights due to the quantum confinement of electrons atoms rearrange themselves 1000 times faster than in conventional bulk crystals nanocrystal size distribution depends sensitively on the growth rate and temperature in unexpected ways Counter-intuitive behavior: producing them quickly leads to lower density of nanocrystals Pb nanocrystals consume the highly disordered Pb wetting layer, creating a smooth buried interface that facilitates electron standing wave states in the nanocrystal Intense x-ray synchrotron radiation from the Advanced Photon Source allows us to see the diffuse scattering signature from less than one atomic layer worth of Pb nanocrystals Pb nanocrystal Disordered Pb wetting layer Si(111) substrate