A View on Fast Magnetization Dynamics: Studies by XPEEM

Understanding the microscopic mechanisms governing fast magnetic switching processes is of high fundamental interest as well as of vital technological importance. A macrospin picture often fails to adequately describe the situation in extended systems. A detailed study of the magnetization dynamics in complex magnetic materials thus requires a real-space mapping of the magnetization distribution in the ground state and of its time evolution. Imaging these transient magnetization distributions on a sub-nanosecond time scale is an experimental challenge, which has been successfully addressed in recent years by time-resolved Kerr and X-ray photoemission microscopies. Soft X-ray photoemission electron microscopy (XPEEM) is known to be an extremely versatile tool to image static domain patterns in chemically complex magnetic systems, combining element selectivity with strong magnetic contrast and high lateral resolution. The choice of different magnetic contrast modes with circularly or linearly polarized light provides access to both ferro-and antiferromagnetically ordered structures. The technique can be extended into the sub-nanosecond time-domain by exploiting the intrinsic time structure of the synchrotron light.