| AVS 62nd International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Tuesday Sessions |
| Session NS+SP-TuM |
| Session: | Nanoscale Imaging and Materials Characterization |
| Presenter: | Joseph McKeown, Lawrence Livermore National Laboratory |
| Authors: | J.T. McKeown, Lawrence Livermore National Laboratory Y. Wu, University of Tennessee J.D. Fowlkes, Oak Ridge National Laboratory P.D. Rack, University of Tennessee G.H. Campbell, Lawrence Livermore National Laboratory |
| Correspondent: | Click to Email |
Core-shell nanoparticles have attracted much attention due to their unique and tunable properties relative to bulk structures of the same materials, making them candidates for a variety of energy- and catalysis-related applications. Intriguing magnetic behavior can be tailored by variation of size, interface, crystal orientation, and composition, and core-shell nanoparticles with noble-metal shells yield novel optical responses and enhanced electrocatalytic activity. The immiscible Co-Cu alloy system is of particular interest, because it combines a strong magnet (Co) with an effective conductor (Cu) that also has a tunable plasmonic resonance. The ability to monitor and characterize these dewetting processes in situwhile the system is evolving can potentially lead to increased control and directed self-assembly. However, in situcharacterization of the dynamics of self-assembly processes has proven extremely challenging, particularly in materials systems that utilize metallic nanoparticles as the dynamics of these processes evolve extremely fast over very small spatial scales. Here, we present a method to synthesize Co@Cu nanoparticles via pulsed-laser-induced dewetting of Co-Cu alloy thin films. We show that this technique effectively synthesizes Co@Cu core-shell particles with controllable sizes ranging from tens to several hundred nanometers. The assembly dynamics during pulsed-laser-induced dewetting of Co-Cu alloy films were revealed using the high spatiotemporal resolution of the dynamic transmission electron microscope (DTEM) at Lawrence Livermore National Laboratory.
Work at Lawrence Livermore National Laboratory was performed under the auspices of the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering for FWP SCW0974 under Contract DE-AC52-07NA27344. Work at the University of Tennessee was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. Research conducted at the Center for Nanophase Materials Sciences is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division of the U.S. Department of Energy, Office of Science, Office of Basic Energy Science.