Magnetic transmission X-ray microscopy:: imaging magnetic domains via the X-ray magnetic circular dichroism

X-ray magnetic circular dichroism (X-MCD), i.e. the dependence of the absorption of circularly polarized X-rays on the magnetization of a ferromagnetic sample used as a contrast mechanism in combination with a high resolution transmission X-ray microscope (TXM) enables a quantitative and element-specific imaging of magnetic structures with a lateral resolution down to about 30 nm. Quantitative information on the local magnetization can be obtained, in particular a separation between spin and orbital moments is possible by applying magneto-optical sum-rules. Images in varying external magnetic fields can be recorded and allow to study magnetization reversal processes within a complete magnetization cycle. Multilayered systems of FeGd and PtCo have been studied. Results on the mechanism of pinning of domain walls as, e.g. the density of pinning centers are presented. (C) 1999 Elsevier Science S.A. All rights reserved.