AVS 63rd International Symposium & Exhibition
    Electronic Materials and Photonics Wednesday Sessions
       Session EM+NS-WeM

Paper EM+NS-WeM10
Designer Nanomaterials by Magnetron Sputtering and Ion Soft Landing

Wednesday, November 9, 2016, 11:00 am, Room 102A

Session: Nanoparticles for Electronics and Photonics
Presenter: Grant Johnson, Pacific Northwest National Laboratory
Authors: G. Johnson, Pacific Northwest National Laboratory
V. Prabhakaran, Pacific Northwest National Laboratory
T. Moser, Michigan Technological University
M.H. Engelhard, Pacific Northwest National Laboratory
N. Browning, Pacific Northwest National Laboratory
J. Laskin, Pacific Northwest National Laboratory
Correspondent: Click to Email
Clusters and nanoparticles comprised of controlled amounts of different atoms are of interest for applications in optics, magnetics, catalysis, sensors, and biotheraputics. Alloy nanoparticles, in particular, may possess enhanced properties compared to single-metal species due to the additional interplay between their different elemental components. By reducing the quantity of precious metals in alloys by substitution with cheaper base metals, it is possible to achieve equivalent or superior performance to noble metal nanoparticles at reduced material cost. In addition, alloying of elements that are immiscible in the bulk is possible at the nanoscale because the enthalpy of mixing decreases and becomes negative at small particle sizes. As a result, a broad array of alloy species may be generated in the form of clusters and nanoparticles. Magnetron sputtering of multiple targets in the same region of gas aggregation is demonstrated to produce ionic alloy clusters and nanoparticles with defined composition and morphology that are not obtainable through solution synthesis. Introduction of reactive gases into the sputtering and aggregation region is shown to result in the formation of complex morphologies. A suite of characterization techniques including atomic force microscopy, scanning and transmission electron microscopy, and x-ray photoelectron spectroscopy is utilized to determine how the size, shape, and elemental composition of soft landed particles may be tuned through variations in source parameters. The electrochemical activity of the soft landed nanomaterials toward the oxygen reduction reaction, a critical process occurring in proton exchange membrane fuel cells, is evaluated ex-situ using cyclic voltammetry in solution and in-situ using an ionic liquid membrane in vacuum.