Internal Seminar: Jerome Vernieres, Gas Phase Synthesis of Fe-based Nanoparticles

Title:

Gas Phase Synthesis of Fe-based Nanoparticles

Abstract:

Magnetron-sputtering inert-gas condensation is an emerging technique offering single-step, chemical-free synthesis of nanoparticles with well-defined morphologies optimized for specific applications. In this talk, a flexible approach to produce Fe nanocubes as building blocks for high-performance NO2 gas sensor devices, and hybrid FeAu nanocubes with magneto-plasmonic properties will be demonstrated. Using various target thicknesses of magnetic materials (Fe) as a new growth parameter give rise to precise control over the size and chemical composition, as well as the shape, while maintaining high-uniformity and consistently sufficient material yield. The effectiveness of the method is demonstrated by the deposition of Fe nanocubes on microhotplate devices, leading to unprecedented NO2 detection performance for Fe-based chemoresistive gas sensors. The exceedingly low detection limit down to 3 ppb is attributed to a morphological change in operando from Fe/Fe-oxide core/shell to specific hollow-nanocube structures, as revealed by in situ environmental transmission electron microscopy.