Condensed-Matter Physics & Materials Science Seminar

Recently a collaboration of BESSY in Berlin and SSRL at Stanford succeeded in exploiting the coherence and tunable polarization of soft X-ray synchrotron radiation for imaging magnetic nanostructures via Fourier Transform Holography. This new lensless imaging technique is based on the direct Fourier inversion of a holographically formed soft x-ray interference pattern. Our implementation is particularly simple and is based on placing the sample behind a lithographically manufactured mask with a micron-sized object aperture and a nano-sized reference pinhole. The technique avoids costly zone plate X-ray lenses as used in conventional X-ray microscopy. By exploiting the magnetic dichroism in resonance at the L3 edges of the magnetic transition metals (wavelength ~ I - 2 nm (700-900 eV), images of magnetic nanostructures have been obtained with a spatial resolution of below 50 nm. Different examples will be presented. 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.

References:

1. Lensless Imaging of Magnetic Nanostructures by X-ray Spectro-Holography
S. Eisebitt, J. Luning, W. F. Schlotter. M. Lorgen. O. Hellwig. W. Eberhardt and J. Stohr,
Nature. 432 (2004) 885.

2. Magnetic Imaging with Soft X-Ray Spectro-Holography
O. Hellwig, S. Eisebitt, W. Eberhardt, J. Luning. W. F. Schlotter and J. Stohr,
J. Appl. Phys. (2006), in print.

Experiments have been performed in collaboration with
Stefan Eisebitt & Wolfgang Eberhardt, BESSY GmbH, Albert-Einstein-Str.l5, 12489 Berlin, GM
Jan Luning, William F. Schlotter and Joachim Stohr
SSRL, Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park CA 94025, USA
and Department of Applied Physics, 316 Via Pueblo Mall, Stanford University, Stanford, CA 94305-4090