Study of in-plane magnetic domains with magnetic transmission x-ray microscopy

Magnetic transmission x-ray microscopy is a novel technique to image elemen t specifically magnetic domain structures. A lateral resolution down to 25 nm is provided by the Fresnel zone plates used as optical elements in soft x-ray microscopy. The magnetic contrast is given by x-ray magnetic circular dichroism, i.e., large magnetic contributions up to 25% to the absorption cross section of circularly polarized x rays that occur in the vicinity of, e.g., the Fe L-3,L-2 edges (706 and 719 eV) and depend on the relative ori entation of the projection of the magnetization of the sample onto the phot on propagation direction. Thus, both in-plane and out-of-plane contribution s to the magnetization are accessible. Here we present images of the magnet ic domain structure of a (3 nm Cr/50 nm Fe/6 nm Cr) thin film system with a preferentially in-plane magnetization recorded at the Fe L edges. The samp les have been prepared by thermal evaporation onto a 100 nm thin Si3N4 memb rane and were mounted under a tilt of 30 degrees with respect to the transm ission direction of the photons in the full-field microscope. Corresponding images taken under a tilt of 0 degrees ruled out out-of-plane contribution s. Images recorded in applied varying external magnetic fields allowed to s tudy the switching behavior. These trial results have a large impact on fur ther investigations of nanostructured magnetic systems, e.g., spintronic de vices and magnetic sensors with magnetic soft x-ray microscopy. (C) 2001 Am erican Institute of Physics.