Neutrons for Functional Materials

Neutrons can be used to study the connection between macroscopic functional properties and microscopic structure of materials—often even in-operando. We utilise the isotope specific sensitivity of neutrons to investigate different nanoparticle-based colloids, including magnetic materials, with a focus on self-assembly.

Self-assembled nanostructures can exhibit collective properties not present in their constituents. Magnetic nanoparticles can for example assemble into chains, clusters or rings with applications as magnetic seals, memory devices or in biomedicine. Neutron reflectivity was used to characterise the self-assembly of magnetite nanoparticles dissolved in water at a silicon substrate both with and without an external magnetic field. Not only the sensitivity of neutrons to magnetic induction is relevant for this kind of research but also their ability to penetrate through the substrate.

Other nanoparticles of interest are cellulose nanoparticles. Doped with gold nanorods they have the potential to be used in optical devices with unique properties or as chirally specific catalysts. To improve the quality and reproducibility of the self-assembly process, we need to understand on a fundamental level how these two types of nanoparticles interact in a liquid state. Small-angle neutron scattering was used to investigate the structure and spacing of these materials including its evolution.

Selected publications