Welcome to the Microspectroscopy Group

Artificial spin ices are periodic arrangements of interacting nanomagnets which allow investigating emergent phenomena in the presence of geometric frustration. Recently, it has been shown that artificial spin ices can be used as building blocks for creating functional materials, such as magnonic crystals. Scientists have now investigated the GHz dynamics in a spin ice with a chiral geometry. They found that the system possesses a rich spin-wave spectrum owing to the presence of anisotropic magnetostatic interactions. These results contribute to the understanding of GHz magnetization dynamics in spin ices and are relevant for the realization of reconfigurable magnonic crystals based on spin ices.

Chemical changes inside of breathable airborne particles can cause reactive oxygen species (ROS) and carbon centered radicals (CCRs) to form, which are harmful to our bodies and induce oxidative stress in lungs. Using X-ray spectromicroscopy at the PolLux beamline and mimicking the environmental and sunlit conditions aerosol particles experience in the atmosphere near the Earth Surface, it was recently found that highly viscous organic particles with low water content can attain high concentrations of ROS and CCRs that persist over long times. Natural particles like these will occur in ambient humidity below 60% and effectively trap ROS and CCRs inside that react when exposed to light.

Employing time-resolved STXM imaging, researchers investigated the emission of spin waves from a magnetic vortex core. By applying static magnetic fields, the control of both the shape of the vortex core and of the spatial profile of the emitted spin waves could be demonstrated, allowing for the fabrication of field-tunable spin wave focusing elements.