Credit: © 2008 APS

X-ray microscopes are widely used for investigating the crystalline structure and physical properties of both organic and inorganic materials. However, the ultimate spatial resolution of X-ray microscopy based on direct irradiation of objects is limited to about 10 nm because of aberrations caused by the components used to guide and focus the X-rays. Now, Christian Schroer and colleagues1 at the Technishe Universität Dresden and the ESRF have combined coherent X-ray diffraction imaging with nanofocused X-ray illumination to image a single 100 nm gold particle with a spatial resolution of about 5 nm.

The researchers found that, by using highly focused coherent X-rays, they could increase the intensity of the X-ray beam and significantly reduce the exposure time for high-resolution imaging. The experiments were carried out at a synchrotron radiation facility, where the gold particle was irradiated with a beam of 'hard' X-rays that had been focused to a diameter of just 100 nm. The image of the gold particle was then reconstructed from its coherent diffraction pattern.

The results are expected to lead to combined coherent X-ray diffraction imaging and scanning microscopy with even higher spatial resolutions, and will be important for single-particle diffraction experiments at future free-electron laser sources.