Bragg coherent diffraction imaging techniques at 3rd and 4th generation light sources

Abstract

Although X-ray crystallography is established as a state of the art imaging technique that has been revolutionary across materials sciences, physics, chemistry, biology and medicine, the imaging of non-crystalline objects is inaccessible by this method. A promising approach that can overcome this challenge is coherent diffractive imaging (CDI). CDI is a lensless microscopy technique that can provide nanoscale images of both non-crystalline and crystalline objects. The morphology, structure and evolution of an object of interest is probed using a coherent source of photons (often X-rays, visible light) or electrons. Coherency is needed for the interference to produce a usable diffraction pattern. While the diffraction pattern contains the magnitude information of the object in reciprocal space, the phase information can be recovered using iterative feedback algorithms, allowing the reconstruction of the image of an object. As no lenses are used, the image is free of aberrations and hence the resolution is limited only by the wavelength of the probe, exposure, and the robustness of the reconstruction algorithm. This technique has proven crucial for imaging of variety of samples, from nanostructures to bio-tissues and individual cells. The aim of this chapter is to provide a clear picture of recent state-of-the-art developments in CDI techniques, and particularly in Bragg Coherent Diffraction Imaging, applied to oxide nanostructures.