Magnetic imaging with high spatial and temporal resolution at the PolLux endstation of the Swiss Light Source

Scanning transmission x-ray microscopy (STXM) is an x-ray microscopy technique that relies on the use of diffractive optics (Fresnel zone plates) to focus a monochromatic x-ray beam onto a spot of an x-ray transparent sample, and record the transmitted x-ray intensity with a suitable detector. By raster scanning the sample with a piezoelectric stage and recording the transmitted intensity at each point of the scan, a STXM image is then formed. STXM imaging combines the elemental sensitivity of monochromatic x-rays with the x-ray magnetic circular dichroism (XMCD) effect, allowing for the imaging of e.g. micro- and nanostructured magnetic materials, and multilayered magnetic systems. Depending on the employed zone plate, spatial resolutions on the order of 10 to 30 nm can be achieved with STXM imaging in the soft x-ray region. Time-resolved STXM imaging in the pump-probe regime is also possible. This is made possible by the use of avalanche photodiodes to detect the x-rays, and allows the achievement of temporal resolutions on the order of 50-100 ps. In this contribution, we present the current status and operation performances of the X07DA PolLux STXM endstation of the Swiss Light Source [1]. In particular, the perfor- mance of the endstation in imaging magnetic systems at high spatial and temporal resolutions will be presented. Furthermore, thanks to its modular design, the PolLux endstation allows for the implementation of specific setups aimed at the imaging of magnetic systems under special configurations. An example of such specific setups, which will be presented in this contribution, is the combination of STXM imaging with electrical transport measurements (e.g. aimed at the measurement of topological contributions of magnetic skyrmions to the anomalous Hall effect [2]).