Name of hosting facility: European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany, https://www.xfel.eu/
Facilities used: EuXFEL, SACLA, KEK-PF/PF-AR, PAL-FEL, ESRF, FLASH
Duration: 3 years
Domains: Materials and Matter, Future Technologies
Description:
The use of metal nanostructures with higher aspect ratios has been extensively utilized in various technical applications, e.g., cancer therapy, photovoltaics, data storage, sensing, and biolabeling, due to their enhanced optical properties. In most applications, localized free electrons on the surface of nanoparticles (NPs), known as to as the localized surface plasmon resonances (LSPRs), are responsible for their enhanced properties and functionalities. Reshaping processes below the melting temperature are linked to the activation energy for surface diffusion, which is related to the surface diffusion coefficient, and it is strongly correlated with the aspect ratio of the NPs. Conventional ex-situ techniques, however, lack the temporal resolution required to disentangle melting-driven phase transitions from surface diffusion-mediated reshaping, leading to discrepancies with theoretical predictions. Our research mainly focused on revealing ultrafast reshaping mechanism and the hidden ultrafast dynamics in both LSPR and thermal diffusion of NPs using pump-probe coherent X-ray diffraction and coherent X-ray diffractive imaging (CXDI) methods.
