Improving the reliability of small- and wide-angle X-ray scattering measurements of anisotropic precipitates in metallic alloys using sample rotation.

Nanometric precipitates in metallic alloys often have highly anisotropic shapes. Given the large grain size and non-random texture typical of these alloys, performing small- and wide-angle X-ray scattering (SAXS/WAXS) measurements on such samples for determining their characteristics (typically size and volume fraction) results in highly anisotropic and irreproducible data. Rotations of flat samples during SAXS/WAXS acquisitions are presented here as a solution to these anisotropy issues.

Metal-ferroelectric supercrystals with periodically curved metallic layers.

Simultaneous manipulation of multiple boundary conditions in nanoscale heterostructures offers a versatile route to stabilizing unusual structures and emergent phases. Here, we show that a stable supercrystal phase comprising a three-dimensional ordering of nanoscale domains with tailored periodicities can be engineered in PbTiO-SrRuO ferroelectric-metal superlattices. A combination of laboratory and synchrotron X-ray diffraction, piezoresponse force microscopy, scanning transmission electron microscopy and phase-field simulations reveals a complex hierarchical domain structure that forms to minimize the elastic and electrostatic energy.

Real- and -space travelling: multi-dimensional distribution maps of crystal-lattice strain (∊) and tilt of suspended monolithic silicon nanowire structures.

Silicon nanowire-based sensors find many applications in micro- and nano-electromechanical systems, thanks to their unique characteristics of flexibility and strength that emerge at the nanoscale. This work is the first study of this class of micro- and nano-fabricated silicon-based structures adopting the scanning X-ray diffraction microscopy technique for mapping the in-plane crystalline strain (∊) and tilt of a device which includes pillars with suspended nanowires on a substrate. It is shown how the micro- and nanostructures of this new type of nanowire system are influenced by critical steps of the fabrication process, such as electron-beam lithography and deep reactive ion etching.

Correlation of Optical, Structural, and Compositional Properties with V-Pit Distribution in InGaN/GaN Multiquantum Wells.

InGaN/GaN double heterostructures and multiquantum wells (MQWs) have been successfully developed since more than 20 years for LED lightning applications. Recent developments show that state-of-the-art LEDs benefit from artificially generated V-pit defects. However, the control of structural and chemical properties plays a tremendous role.

The Nanodiffraction beamline ID01/ESRF: a microscope for imaging strain and structure.

The ID01 beamline has been built to combine Bragg diffraction with imaging techniques to produce a strain and mosaicity microscope for materials in their native or operando state. A scanning probe with nano-focused beams, objective-lens-based full-field microscopy and coherent diffraction imaging provide a suite of tools which deliver micrometre to few nanometre spatial resolution combined with 10 strain and 10 tilt sensitivity. A detailed description of the beamline from source to sample is provided and serves as a reference for the user community.

In situ structural evolution of single particle model catalysts under ambient pressure reaction conditions.

The catalytic activity of metal nanoparticles can be altered by applying strain, which changes the crystalline lattice spacing and modifies the electronic properties of the metal. Understanding the role of elastic strain during catalytic reactions is thus crucial for catalyst design. Here, we show how single highly faceted Pt nanoparticles expand or contract upon interaction with different gas atmospheres using in situ nano-focused coherent X-ray diffraction imaging.

X-ray Excited Optical Fluorescence and Diffraction Imaging of Reactivity and Crystallinity in a Zeolite Crystal: Crystallography and Molecular Spectroscopy in One.

Structure-activity relationships in heterogeneous catalysis are challenging to be measured on a single-particle level. For the first time, one X-ray beam is used to determine the crystallographic structure and reactivity of a single zeolite crystal. The method generates μm-resolved X-ray diffraction (μ-XRD) and X-ray excited optical fluorescence (μ-XEOF) maps of the crystallinity and Brønsted reactivity of a zeolite crystal previously reacted with a styrene probe molecule.

Microstrain distribution mapping on CuInSe2 thin films by means of electron backscatter diffraction, X-ray diffraction, and Raman microspectroscopy.

The investigation of the microstructure in functional, polycrystalline thin films is an important contribution to the enhanced understanding of structure-property relationships in corresponding devices. Linear and planar defects within individual grains may affect substantially the performance of the device. These defects are closely related to strain distributions.

X-ray Excited Optical Fluorescence and Diffraction Imaging of Reactivity and Crystallinity in a Zeolite Crystal: Crystallography and Molecular Spectroscopy in One.

Structure-activity relationships in heterogeneous catalysis are challenging to be measured on a single-particle level. For the first time, one X-ray beam is used to determine the crystallographic structure and reactivity of a single zeolite crystal. The method generates μm-resolved X-ray diffraction (μ-XRD) and X-ray excited optical fluorescence (μ-XEOF) maps of the crystallinity and Brønsted reactivity of a zeolite crystal previously reacted with a styrene probe molecule.

Structural Mapping of Functional Ge Layers Grown on Graded SiGe Buffers for sub-10 nm CMOS Applications Using Advanced X-ray Nanodiffraction.

We report a detailed advanced materials characterization study on 40 nm thick strained germanium (Ge) layers integrated on 300 mm Si(001) wafers via strain-relaxed silicon-germanium (SiGe) buffer layers. Fast-scanning X-ray microscopy is used to directly image structural inhomogeneities, lattice tilt, thickness, and strain of a functional Ge layer down to the sub-micrometer scale with a real space step size of 750 μm. The structural study shows that the metastable Ge layer, pseudomorphically grown on Si(0.

Imaging Structure and Composition Homogeneity of 300 mm SiGe Virtual Substrates for Advanced CMOS Applications by Scanning X-ray Diffraction Microscopy.

Advanced semiconductor heterostructures are at the very heart of many modern technologies, including aggressively scaled complementary metal oxide semiconductor transistors for high performance computing and laser diodes for low power solid state lighting applications. The control of structural and compositional homogeneity of these semiconductor heterostructures is the key to success to further develop these state-of-the-art technologies. In this article, we report on the lateral distribution of tilt, composition, and strain across step-graded SiGe strain relaxed buffer layers on 300 mm Si(001) wafers treated with and without chemical-mechanical polishing.