08 Fakultät Mathematik und Physik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/9

Browse

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Transformable plasmonic helix with swinging gold nanoparticles
    (2022) Peil, Andreas; Zhan, Pengfei; Duan, Xiaoyang; Krahne, Roman; Garoli, Denis; M. Liz‐Marzán, Luis; Liu, Na
    Control over multiple optical elements that can be dynamically rearranged to yield substantial three‐dimensional structural transformations is of great importance to realize reconfigurable plasmonic nanoarchitectures with sensitive and distinct optical feedback. In this work, we demonstrate a transformable plasmonic helix system, in which multiple gold nanoparticles (AuNPs) can be directly transported by DNA swingarms to target positions without undergoing consecutive stepwise movements. The swingarms allow for programmable AuNP translocations in large leaps within plasmonic nanoarchitectures, giving rise to tailored circular dichroism spectra. Our work provides an instructive bottom‐up solution to building complex dynamic plasmonic systems, which can exhibit prominent optical responses through cooperative rearrangements of the constituent optical elements with high fidelity and programmability.
  • Thumbnail Image
    ItemOpen Access
    Stabilizing γ‐MgH2 at nanotwins in mechanically constrained nanoparticles
    (2021) Kammerer, Jochen A.; Duan, Xiaoyang; Neubrech, Frank; Schröder, Rasmus R.; Liu, Na; Pfannmöller, Martin
    Reversible hydrogen uptake and the metal/dielectric transition make the Mg/MgH2 system a prime candidate for solid‐state hydrogen storage and dynamic plasmonics. However, high dehydrogenation temperatures and slow dehydrogenation hamper broad applicability. One promising strategy to improve dehydrogenation is the formation of metastable γ‐MgH2. A nanoparticle (NP) design, where γ‐MgH2 forms intrinsically during hydrogenation is presented and a formation mechanism based on transmission electron microscopy results is proposed. Volume expansion during hydrogenation causes compressive stress within the confined, anisotropic NPs, leading to plastic deformation of β‐MgH2 via (301)β twinning. It is proposed that these twins nucleate γ‐MgH2 nanolamellas, which are stabilized by residual compressive stress. Understanding this mechanism is a crucial step toward cycle‐stable, Mg‐based dynamic plasmonic and hydrogen‐storage materials with improved dehydrogenation. It is envisioned that a more general design of confined NPs utilizes the inherent volume expansion to reform γ‐MgH2 during each rehydrogenation.