Figure 2
(a) STXM image of the central area of the spin torque device including the two polarizers and the magnetic pillar in the center. The upper image shows the direct absorption contrast caused by the metallic layers. The images are recorded at the absorption maximum of Co, i.e. E = 780 eV. The lower image shows the contrast given by different absorption of the transmitted x-rays due to XMCD indicating the magnetization directions of the two polarizers. In our images black structures correspond to the magnetization pointing to the right side (positive values of H) and white structures to the magnetization pointing to the left side (negative H). This contrast is achieved by depicting the normalized intensity difference cXMCD = 
of the two images taken at different polarizations. (b) Zoom on the central pillar and construction of the magnetic contrast images. The central region containing the nanopillar (highlighted by the dashed circle) is scanned with circularly polarized x-rays. The contrast of spin-polarized regions depends on the polarization, thus subtraction of the images shows the magnetic contrast in the structure. It can be seen in (a) that the Au leads connecting the polarizers to the current pulser disappear in the magnetic contrast image.
