X-ray holographic imaging of magnetic order in patterned Co/Pd multilayers

We address the role of lateral confinement in determining the micromagnetic structure of small objects featuring perpendicular magnetic anisotropy. We have imaged the spatial distribution of magnetic domains in Co/Pd multilayered objects by x-ray holography in transmission mode, a technique based on resonant coherent scattering of polarized x rays. In addition to high spatial resolution and magnetic sensitivity, x-ray holography features chemical selectivity and probes the entire bulk of the magnetic sample. By analyzing and comparing images of several magnetic objects (squares and rectangles with 0.4-3-mu m lateral sizes) that underwent the same preparation procedure and magnetic history, we highlight the influence of the object shape and of its orientation with respect to an external field in determining the remanent magnetic microstructure. The discussion of our results is backed by micromagnetic calculations.