title: Reversible Shape and Plasmon Tuning in Hollow AgAu Nanorods.
abstract: The internal structure of hollow AgAu nanorods created by partial galvanic replacement was manipulated reversibly, and its effect on optical properties was mapped with nanometer resolution. Using the electron beam in a scanning transmission electron microscope to create solvated electrons and reactive radicals in an encapsulated solution-filled cavity in the nanorods, Ag ions were reduced nearby the electron beam, reshaping the core of the nanoparticles without affecting the external shape. The changes in plasmon-induced near-field properties were then mapped with electron energy-loss spectroscopy without disturbing the internal structure, and the results are supported by finite-difference time-domain calculations. This reversible shape and near-field control in a hollow nanoparticle actuated by an external stimulus introduces possibilities for applications in reprogrammable sensors, responsive materials, and optical memory units. Moreover, the liquid-filled nanorod cavity offers new opportunities for in situ microscopy of chemical reactions.
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Yazdi
authors.affiliation: Center for Optics, Photonics and Lasers (COPL), Department of Chemistry, Laval University , Ville de Québec, Québec, Canada , G1 V 0A6.
authors.forename: Josée R
authors.initials: JR
authors.lastname: Daniel
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Large
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: George C
authors.initials: GC
authors.lastname: Schatz
authors.affiliation: Center for Optics, Photonics and Lasers (COPL), Department of Chemistry, Laval University , Ville de Québec, Québec, Canada , G1 V 0A6.
authors.forename: Denis
authors.initials: D
authors.lastname: Boudreau
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.|Department of Chemistry, Rice University , Houston, Texas 77005, United States.
authors.forename: Emilie
authors.initials: E
authors.lastname: Ringe
keywords: Localized surface plasmon resonance (LSPR); bimetallic nanorods; electron energy-loss spectroscopy (EELS); galvanic replacement; plasmon near-field; reconfigurable systems