Date: 09.12.2022, Time: 15:30h

Location: Kleiner Physik-Hörsaal N 020, Fakultät für Physik
The talk will be streamed online.

Prof. Emilie Ringe
Professor of Synthetic and Natural Nanomaterials, University of Cambridge

Localized surface plasmon resonances (LSPRs) have a broad technology potential as an attractive platform for surface-enhanced spectroscopies, non-bleaching labels, hyperthermal cancer therapy, waveguides, and so on. One of the newest metals for plasmonics is magnesium. It is earth-abundant, biocompatible, and has a higher plasmonic quality factor than aluminum across the visible (and than gold and copper in the blue). In the past ten years, several fabricated magnesium structures have emerged, demonstrating the optical behaviors expected of plasmonic metals. Our group has chosen a different approach: we have developed colloidal, scalable batch and flow syntheses capable of size control from ~50 to 1000 nm. This enabled to study the fascinating size and shape-dependent optical, chemical, crystallographic and catalytic properties of these novel structures.

This talk will review the advances we have made over the past four years on magnesium plasmonics. The unusual shapes of single crystal and twinned magnesium crystals, owing to its HCP structure, will first be discussed, followed by the formation and stability of the native oxide layer. Then, approaches to control nanoparticle size and shape will be presented, followed by experimental (optical, EELS) and numerical results on their effect on plasmonic properties of colloidal magnesium. Our approach to exploiting the chemical reactivity of magnesium for galvanic replacement, and the catalytic and photocatalytic activity of the resulting Mg-M (M=Ag, Au, Cu, Fe, Pd) bimetallic structures obtained, will be reviewed.