Hard X-ray Microscopy with Elemental, Chemical and Structural Contrast

Abstract

We review hard X-ray microscopy techniques with a focus on scanning microscopy with synchrotron radiation. Its strength compared to other microscopies is the large penetration depth of hard x rays in matter that allows one to investigate the interior of an object without destructive sample preparation. In combination with tomography, local information from inside of a specimen can be obtained, even from inside special non-ambient sample environments. Different X-ray analytical techniques can be used to produce contrast, such as X-ray absorption, fluorescence, and diffraction, to yield chemical, elemental, and structural information about the sample, respectively. This makes X-ray microscopy attractive to many fields of science, ranging from physics and chemistry to materials, geo-, and environmental science, biomedicine, and nanotechnology. Our scanning microscope based on nanofocusing refractive X-ray lenses has a routine spatial resolution of about 100 nm and supports the contrast mechanisms mentioned above. In combination with coherent X-ray diffraction imaging, the spatial resolution can be improved to the 10 nm range. The current state-of-the-art of this technique is illustrated by several examples, and future prospects of the technique are given.

Imaging Catalysts at Work: A Hierarchical Approach from the Macro‐ to the Meso‐ and Nano‐scale

“…This technique has not been applied to catalysis yet, but quantitative high‐resolution high‐contrast images of a microchip87 and of an ensemble of 30–50 nm gold particles on a silicon nitride membrane have been studied successfully using X‐rays (Figure 12, ref. 88). In addition, 2‐5 nm particles have recently been studied using 30 keV electrons in an SEM,89 demonstrating the potential of this technique.…”

“…The spatial resolution of ptychographic imaging using X‐rays is presently a few tens of nm, limited primarily by the mechanical stability of the X‐ray microscope and by aspects of data acquisition and interpretation. Although only a few experiments have been performed so far,3e, 88, 90 in principle all coherent diffraction imaging techniques can be combined with X‐ray absorption spectroscopy.…”

Nuclear photonics

“…2 as strong excitations for potential applications. The low-lying M1 excitation can be employed via Nuclear Resonance Fluorescence (NRF) using focusing lenses for tomography and microscopy with µm resolution [11]. In Fig.…”

Stability of a Bifunctional Cu-Based Core@Zeolite Shell Catalyst for Dimethyl Ether Synthesis Under Redox Conditions Studied by Environmental Transmission Electron Microscopy andIn SituX-Ray Ptychography

“…Although the spatial resolution with hard X-rays is limited, they offer a higher penetration depth and allow imaging under more realistic reaction conditions (de Smit et al, 2008; de Groot et al, 2010; Falcone et al, 2011; Cats et al, 2013) and thus the complementary use of these electron and X-ray microscopy techniques is beneficial (Thomas & Hernandez-Garrido, 2009; Li et al, 2015 b ; Stach et al, 2015). In particular, hard X-ray ptychography (Schroer et al, 2010; Høydalsvik et al, 2014) as a high-resolution X-ray microscopy technique has reached spatial resolutions below 10 nm (Vila-Comamala et al, 2011; Schropp et al, 2012) and is thus attractive for in situ studies (Baier et al, 2016 a ). In addition, the application of resonant X-ray ptychography offers chemical contrast (Beckers et al, 2011; Hoppe et al, 2013), and if the coherent small-angle X-ray scattering (SAXS) contribution is analyzed, further information on nanostructured materials can be obtained, for example from in situ anomalous SAXS (Andreasen et al, 2006).…”