title: Size- and Shape-Controlled Synthesis and Properties of Magnetic-Plasmonic Core-Shell Nanoparticles.
abstract: Magnetic-plasmonic core-shell nanomaterials offer a wide range of applications across science, engineering and biomedical disciplines. However, the ability to synthesize and understand magnetic-plasmonic core-shell nanoparticles with tunable sizes and shapes remains very limited. This work reports experimental and computational studies on the synthesis and properties of iron oxide-gold core-shell nanoparticles of three different shapes (sphere, popcorn and star) with controllable sizes (70 to 250 nm). The nanoparticles were synthesized via a seed-mediated growth method in which newly formed gold atoms were added onto gold-seeded iron oxide octahedrons to form gold shell. The evolution of the shell into different shapes was found to occur after the coalescence of gold seeds, which was achieved by controlling the amount of additive (silver nitrate) and reducing agent (ascorbic acid) in the growth solution. First principles calculation, together with experimental results, elucidated the intimate roles of thermodynamic and kinetic parameters in the shape-controlled synthesis. Both discrete dipole approximation calculation and experimental results showed that the nanopopcorns and nanostars exhibited red-shifted plasmon resonance compared with the nanospheres, with the nanostars giving multispectral feature. This research has made a great step further in manipulating and understanding magnetic-plasmonic hybrid nanostructures and will make important impact in many different fields.
authors.affiliation: Department of Chemistry, The University of Memphis, Memphis, TN 38152.
authors.forename: Elyahb Allie
authors.initials: EA
authors.lastname: Kwizera
authors.affiliation: Department of Chemistry, The University of Memphis, Memphis, TN 38152.
authors.forename: Elise
authors.initials: E
authors.lastname: Chaffin
authors.affiliation: Department of Physics and Materials Science, The University of Memphis, Memphis, TN 38152.
authors.forename: Xiao
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Chemistry, University of Arkansas, Fayetteville, AR 72071.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Chen
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zou
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Gai
authors.affiliation: Department of Chemistry, The University of Memphis, Memphis, TN 38152.
authors.forename: Saheel
authors.initials: S
authors.lastname: Bhana
authors.affiliation: Department of Chemistry, The University of Memphis, Memphis, TN 38152.
authors.forename: Ryan
authors.initials: R
authors.lastname: O'Connor
authors.affiliation: Department of Physics and Materials Science, The University of Memphis, Memphis, TN 38152.
authors.forename: Lijia
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Physics and Materials Science, The University of Memphis, Memphis, TN 38152.
authors.forename: Hitesh
authors.initials: H
authors.lastname: Adhikari
authors.affiliation: Department of Physics and Materials Science, The University of Memphis, Memphis, TN 38152.
authors.forename: Sanjay R
authors.initials: SR
authors.lastname: Mishra
authors.affiliation: Department of Chemistry, The University of Memphis, Memphis, TN 38152.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemistry, The University of Memphis, Memphis, TN 38152.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Huang