RQMP Research Seminar

Magnesium Nanoparticles: Nanoplasmonics spanning the UV, Visible, and Near-IR

Émilie Ringe

Department of Earth Sciences & Department of Materials Science and Metallurgy
University of Cambridge

Localized surface plasmon resonances have attracted much attention due to their ability to enhance light-matter interactions and manipulate light at the sub-wavelength level. Recently, alternatives to the rare and expensive noble metals Ag and Au have been sought for more sustainable and large-scale plasmonic utilization. Mg supports plasmon resonances, is one of the most abundant elements in earth’s crust, and is fully biocompatible, making it an attractive framework for plasmonics.

This talk will discuss our group’s recent theoretical, numerical, and experimental results on the synthesis and characterization of colloidal Mg nanoparticles. I will first discuss the hexagonal, folded, and kite-like shapes we observe and model, and their significance for the understanding of twinning at the nanoscale in hexagonal and other systems. Then, the optical response of Mg nanoparticles is overviewed, highlighting Mg’s ability to sustain localized surface plasmon resonances across the ultraviolet, visible, and near-infrared electromagnetic ranges. The various resonant modes of hexagons, leading to the highly localized electric field characteristic of plasmonic behavior, are presented numerically and experimentally. The evolution of these modes and associated field from hexagons to the lower symmetry folded structures is then probed, again by matching simulations, optical, and electron spectroscopy data. Lastly, results demonstrating the opportunities and challenges related to the high chemical reactivity of Mg are discussed, including surface oxide formation and galvanic replacement as a synthetic tool for bimetallics.