Advanced Magnetic Nanostructure Characterization via Resonant Soft X-Ray Spectro Holography Imaging in Combination with Microscopic Hysteresis Loop Analysis

In this article the coherence and tunable polarization of soft X-ray synchrotron radiation for imaging magnetic nanostructures via Fourier Transform Holography is discussed. This new lens-less imaging technique is based on the direct Fourier inversion of a holographically formed soft X-ray interference pattern. This is based on placing the sample behind a lithographically manufactured mask with a micron-sized sample aperture and a nano-sized reference hole. By exploiting the magnetic dichroism in resonance at the L3 edges of the magnetic transition metals (wavelength ~ 1-2 nm (700-900 eV)), images of magnetic nanostructures have been obtained with a spatial resolution of 50 nm. The technique is transferable to a wide variety of specimen, appears scalable to diffraction-limited resolution (about 2 nm), and is well suited for ultra-fast single-shot imaging with future X-ray free electron laser sources.