title: Single Particle Deformation and Analysis of Silica-Coated Gold Nanorods before and after Femtosecond Laser Pulse Excitation.
abstract: We performed single particle deformation experiments on silica-coated gold nanorods under femtosecond (fs) illumination. Changes in the particle shape were analyzed by electron microscopy and associated changes in the plasmon resonance by electron energy loss spectroscopy. Silica-coated rods were found to be more stable compared to uncoated rods but could still be deformed via an intermediate bullet-like shape for silica shell thicknesses of 14 nm. Changes in the size ratio of the rods after fs-illumination resulted in blue-shifting of the longitudinal plasmon resonances. Two-dimensional spatial mapping of the plasmon resonances revealed that the flat side of the bullet-like particles showed a less pronounced longitudinal plasmonic electric field enhancement. These findings were confirmed by finite-difference time-domain (FDTD) simulations. Furthermore, at higher laser fluences size reduction of the particles was found as well as for particles that were not completely deformed yet.
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University , Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Wiebke
authors.initials: W
authors.lastname: Albrecht
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University , Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Tian-Song
authors.initials: TS
authors.lastname: Deng
authors.affiliation: Electron Microscopy for Materials Research (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Goris
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University , Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Marijn A
authors.initials: MA
authors.lastname: van Huis
authors.affiliation: Electron Microscopy for Materials Research (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Bals
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University , Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Alfons
authors.initials: A
authors.lastname: van Blaaderen
keywords: EELS; Gold nanorods; deformation; femtosecond laser excitation