Recent Coherent X-ray Literature Round-Up

Electrospray approach to single-particle diffraction at XFEL facilities:

M. Bogan, W. Benner, S. Boutet et al., “Single Particle X-ray Diffractive Imaging,” Nano Letters 8, 310-316 (2008)

A study of SiN etched “logo” pattern x-ray induced destruction, similar to Chapman’s Nature Physics 2006 work (Cowboys holding hands logo, doi:10.1038/nphys461):

A. Barty, S. Boutet, M. J. Bogan et al., “Ultrafast single-shot diffraction imaging of nanoscale dynamics,” Nat Photon 2, 415-419 (2008)

Lens-less imaging of Fresnel Zone Plate using ptychography – scanning coherent diffraction – improvement in resolution and illumination function from FZP reconstruction by Rodenburg et al. PRL 98, 034801 (2007):

P. Thibault, M. Dierolf, A. Menzel et al., “High-Resolution Scanning X-ray Diffraction Microscopy,” Science321, 379-382 (2008)

Tabletop coherent soft x-ray microscopy by UColorado group – an exciting alternative to large XFEL machines:

R. L. Sandberg, C. Song, P. W. Wachulak et al., “High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution,” Proceedings of the National Academy of Sciences of the United States of America 105, 24-7 (2008)

X-ray holography with 5 reference beams is obviously better than holography with 3 or 1 reference beams. How about 1,000,000 reference beams? This is what can be accomplished with uniformly redundant arrays:

S. Marchesini, S. Boutet, A. E. Sakdinawat et al., “Massively parallel X-ray holography,” Nat Photon 2, 560-563 (2008)

Coherent imaging of 80-100nm particle (in SAXS mode, similar to work by Miao group) with 5nm resolution, but done at 15 keV. Coherent fraction of the beam drops off as lambda^2, and efficiency of area x-ray detectors is substantially reduced at higher energies too. But at higher energies one can capture more of the Q range for the same solid angle defined by scattering geometry. Still, 5 nm number is better resolution that I expected – this should imply there are at least 15-20 highly visible fringes in diffraction pattern, instead of 7 or so. Maybe it’s log scale of intensity that hides extra fringes…

C. G. Schroer, P. Boye, J. M. Feldkamp et al., “Coherent X-Ray Diffraction Imaging with Nanofocused Illumination,” Physical Review Letters 101, 090801-4 (2008)

A review article on coherent x-ray diffractive imaging of small particles:

J. Miao, T. Ishikawa, Q. Shen and T. Earnest, “Extending X-ray crystallography to allow the imaging of noncrystalline materials, cells, and single protein complexes,” Annual Review of Physical Chemistry 59, 387-410 (2008)

First example of x-ray holography in hard x-ray regime. Sample preparation is quite a bit more challenging.

L. Stadler, C. Gutt, T. Autenrieth et al., “Hard X Ray Holographic Diffraction Imaging,” Physical Review Letters 100, 245503-4 (2008)

More coherent x-ray lens-less image reconstructions

New paper in Science by Pierre Thibault et al. “High-Resolution Scanning X-ray Diffraction Microscopy” Science 321, 379 (2008).

Authors use an approach identical to ptychography  to demonstrate the power of the technique by reconstructing the Fresnel Zone Plate – similar to work by Rodenburg et al., PRL 98, 034801 (2007).

John Miao and his UCLA group has used lensless imaging to reconstruct image of a single virus:

C. Song et al., “Quantitative Imaging of Single, Unstained Viruses with Coherent X-rays” arXiv:0806.2875.

And Stadler et al. “Hard X Ray Holographic Diffraction Imaging” Phys. Rev. Lett. 100, 245503 (2008) show that the x-ray holographic approach similar to the one previously used by Eisebitt et al., Nature 432, 885 (2004) works in hard-xray regime as should be expected. They cleverly used five carefully positioned nanoparticles as the negative sources of reference beam, and successfully demonstrated that letter “P” can be reconstructed, adding to an impressive alphabet of reconstructed letters and logos. While use of hard x-rays paves the road for imaging of thick speciments, it’s not clear if one could take advantage of the same principle in high-angle diffraction geometry, which is where real action is for hard x-rays.

Giant molecules or tiny crystals?

Nature Materials has a News and Views article by Ian Robinson titled “Coherent diffraction: Giant molecules or tiny crystals?”, which reviews recent coherent electron diffraction results by Huang et al. featured here earlier. One of the interesting points made in this mini-review is the phase diagram on the left showing a transition from bulk cubic crystal to decahedral and icosahedral structures, including quasi-molten and liquid phases.