Condensed Matter Seminar: Dr Simone Finizio, Paul Scherrer Institut (PSI)

Dr Simone Finizio, of the Micro Spectroscopy Group, Paul Scherrer Institut (PSI), Switzerland, will be presenting a seminar on his research. All are welcome to attend.

The PolLux endstation of the Swiss Light Source: a soft X-ray microscope for time-resolved nanomagnetism

Abstract: Scanning transmission x-ray microscopy (STXM) is a synchrotron-based non-invasive x-ray microscopy technique that can be employed for the investigation of micro- and nanostructured materials.

This technique combines a high spatial resolution (for soft x-rays on the order of 10-15 nm) with a high temporal resolution (depending on the filling pattern of the synchrotron light source, either on the order of 10 or 100 ps). Furthermore, thanks to the use of monochromatic x-rays as probing mechanism, element-sensitive imaging can be carried out with STXM. The typical soft x-ray photon energies available (between ca. 100 eV and 2000 eV) allow the investigation of both carbon-based systems (e.g. polymers) and metallic systems (e.g. based on 3d transition metals).

Furthermore, the elemental sensitivity of this technique, combined with the x-ray magnetic circular dichroism (XMCD) effect, allows for the investigation of the local magnetic configuration of magnetic materials and multilayers with sub-μm spatial and sub-ns temporal resolution. In this presentation, an overview of the PolLux STXM endstation of the Swiss Light Source will be given. In particular, the FPGA-based time-resolved acquisition system installed at the PolLux endstation, which allows for the acquisition of time-resolved images with sub-ns temporal resolution, will be presented in detail.

Finally, several examples of projects that employed the instrumentation available at the PolLux endstation for the investigation of the magnetization dynamics at the nanoscale will be presented. In particular, the quasi-static and time-resolved imaging of magnetic vortex, domain wall, and Skyrmion dynamics will be presented in detail.

Host: Dr Satoshi Sasaki.