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We here present a generic methodology enabling the accelerated optimization of the composition and processes conditions for functional solution-processable materials compatible with later transfer of optimized conditions to scaled device manufacturing. In combinatorial slot-die coating, two or more precursor inks are fed with different rates into the slot-die enabling fast screening of the precursor solution composition on coating property in one experimental run, which can either be implemented as consecutive coatings with different compositions or as a continuous compositional gradient. As a first example, we here present combinatorially slot-die coated halide perovskite thin-films ranging from the precursor compositions of pure formamidinium lead iodide, FAPbI3, to methylammonium lead bromide, MAPbBr3. In this series, both the optical and morphological properties of the deposited thin-films change dramatically. An increasing faction of MAPbBr3 resulted in larger optical bandgaps. At very high MAPbBr3 ratios, differences in the thin-film crystallization kinetics due to the simultaneous change of the precursor solution solvent resulted in thin-films with low quality morphology. The spatial compositional homogeneity of the coated thin-films was characterized by grazing incidence wide angle X-ray scattering mapping. We fabricated inverted perovskite solar cells in the full compositional range and found a performance maximum for FAPbI3-richer devices with a MAPbBr3-content of 20 mol%. The performance maximum can be rationalized with the improved thermodynamic stability of the halide perovskite crystal structure due to a more ideal tolerance factor upon incorporation of the smaller methylammonium cation and bromide anion into the crystal structure. At high MAPbBr3-content, the device performance drops due to two effects: light-induced phase-segregation and a dramatically decreased thin-film morphology exhibiting pinholes. The example highlights the critical balance of precursor solution composition and processing conditions as the crystallization kinetics critically affect the resulting thin-film quality and morphology. This generic methodology can be further optimized and exploited to identify optimal precursor solution compositions and process conditions to achieve high-quality thin films with a target composition and sample morphology with high experimental throughput.

Vaterite is the thermodynamically least stable phase of the three anhydrous calcium carbonate phases. So far there have been no reports showing the synthesis of pure phase vaterite single crystals ...

Biofilms are multicellular microbial communities that encase themselves in an extracellular matrix (ECM) of secreted biopolymers and attach to surfaces and interfaces. Bacterial biofilms are detrimental in hospital and industrial settings, but they can be beneficial in agricultural contexts. An essential property of biofilms that grants them with increased survival relative to planktonic cells is phenotypic heterogeneity; the division of the biofilm population into functionally distinct subgroups of cells. Phenotypic heterogeneity in biofilms can be traced to the cellular level, however, the molecular structures and elemental distribution across whole biofilms as well as possible linkages between them remain unexplored. Mapping X-ray diffraction (XRD) across intact biofilms in time and space, we revealed the dominant structural features in Bacillus subtilis biofilms, stemming from matrix components, spores and water. By simultaneously following the X-ray fluorescence (XRF) signal of biofilms and isolated matrix components, we discovered that the ECM preferentially binds calcium ions over other metal ions, specifically, zinc, manganese and iron. These ions, remaining free to flow below macroscopic wrinkles that act as water channels, eventually accumulate and lead to sporulation. The possible link between ECM properties, regulation of metal ion distribution and sporulation across whole intact biofilms unravels the importance of molecular-level heterogeneity in shaping biofilm physiology and development.Significance StatementBiofilms are multicellular soft microbial communities that are able to colonize synthetic surfaces as well as living organisms. To survive sudden environmental changes and efficiently share their common resources, cells in a biofilm divide into subgroups with distinct functions, leading to phenotypic heterogeneity. Here, by studying intact biofilms by synchrotron X-ray diffraction and fluorescence, we revealed correlations between biofilm macroscopic architectural heterogeneity and the spatio-temporal distribution of extracellular matrix, spores, water and metal ions. Our findings demonstrate that biofilm heterogeneity is not only affected by local genetic expression and cellular differentiation, but also by passive effects resulting from the physicochemical properties of the molecules secreted by the cells, leading to differential distribution of nutrients that propagates through macroscopic length scales.

To accelerate the materials discovery and development process for a sustainable technology advancement it is imperative to explore and develop combined high throughput material synthesis and analysis workflows. In this work, we investigate a method of combinatorial inkjet printing to tune the composition of the inorganic cesium lead mixed halide perovskite solid solution, CsPb BrxI1 amp; 8722;x 3. The compositional variation is achieved by simultaneous printing of different precursor inks with multiple printheads and controlled by varying the number of droplets printed by each printhead throughout the sample. The droplet placement is optimised through an algorithm that allows maximum mixing of the combined inks. The local compositional homogeneity of thin film samples was investigated as a function of the printing resolution by micrometer resolution X ray fluorescence and synchrotron based grazing incidence wide angle X ray scattering. We show that a combinatorial library of ten compositions between CsPbI3 and CsPbBr2I, printed using the developed algorithm, is locally homogeneous for the optimised printing parameters. An implementation of the algorithm in the high level programming language Python is provided for easy use in other systems

Significance Biofilms are multicellular, soft microbial communities that are able to colonize synthetic surfaces as well as living organisms. To survive sudden environmental changes and efficiently share their common resources, cells in a biofilm divide into subgroups with distinct functions, leading to phenotypic heterogeneity. Here, by studying intact biofilms by synchrotron X-ray diffraction and fluorescence, we revealed correlations between biofilm macroscopic, architectural heterogeneity and the spatiotemporal distribution of extracellular matrix, spores, water, and metal ions. Our findings demonstrate that biofilm heterogeneity is not only affected by local genetic expression and cellular differentiation but also by passive effects resulting from the physicochemical properties of the molecules secreted by the cells, leading to differential distribution of nutrients that propagate through macroscopic length scales., Biofilms are multicellular microbial communities that encase themselves in an extracellular matrix (ECM) of secreted biopolymers and attach to surfaces and interfaces. Bacterial biofilms are detrimental in hospital and industrial settings, but they can be beneficial, for example, in agricultural as well as in food technology contexts. An essential property of biofilms that grants them with increased survival relative to planktonic cells is phenotypic heterogeneity, the division of the biofilm population into functionally distinct subgroups of cells. Phenotypic heterogeneity in biofilms can be traced to the cellular level; however, the molecular structures and elemental distribution across whole biofilms, as well as possible linkages between them, remain unexplored. Mapping X-ray diffraction across intact biofilms in time and space, we revealed the dominant structural features in Bacillus subtilis biofilms, stemming from matrix components, spores, and water. By simultaneously following the X-ray fluorescence signal of biofilms and isolated matrix components, we discovered that the ECM preferentially binds calcium ions over other metal ions, specifically, zinc, manganese, and iron. These ions, remaining free to flow below macroscopic wrinkles that act as water channels, eventually accumulate and may possibly lead to sporulation. The possible link between ECM properties, regulation of metal ion distribution, and sporulation across whole, intact biofilms unravels the importance of molecular-level heterogeneity in shaping biofilm physiology and development.

We present a novel method of temporal modulation of X-ray radiation for time resolved experiments. To control the intensity of the X-ray beam, the Bragg reflection of a piezoelectric crystal is modified using comb-shaped electrodes deposited on the crystal surface. Voltage applied to the electrodes induces a periodic deformation of the crystal that acts as a diffraction grating, splitting the original Bragg reflection into several satellites. A pulse of X-rays can be created by rapidly switching the voltage on and off. In our prototype device the duty cycle was limited to ∼1 ns by the driving electronics. The prototype can be used to generate X-ray pulses from a continuous source. It can also be electrically correlated to a synchrotron light source and be activated to transmit only selected synchrotron pulses. Since the device operates in a non-resonant mode, different activation patterns and pulse durations can be achieved.

The possibilities are presented of X-ray diffraction methods for studying the propagation of surface acoustic waves (SAWs) in solids, including diffraction under total external reflection conditions and Bragg diffraction, using acoustically modulated X-ray multilayer mirrors and crystals. SAW propagation was studied using both meridional and sagittal diffraction geometries where the SAW wavevectors and X-ray photons are collinear or perpendicular, respectively. SAW propagation in a crystal leads to sinusoidal modulation of the crystal lattice and the appearance of diffraction satellites on the rocking curve. The intensities and angular positions of these diffraction satellites are determined by the SAW wavelength, amplitude and attenuation. Therefore, diffraction methods allow the analysis of the SAW propagation process and determination of SAW parameters. The influence of X-ray energy on diffraction by acoustically modulated crystals is studied for the first time. It is shown that changes in the X-ray energy can change the angular region where diffraction satellites exist under conditions of total external reflection. By contrast, in the Bragg diffraction region changes in the X-ray photon energy lead to changes in the X-ray penetration depth into the crystal and redistribution of the diffracted intensity among diffraction satellites, but do not change the angular divergence between diffraction satellites on the rocking curve. It is also shown that, in X-ray diffraction on acoustically modulated crystals on a number of successive reflections, a decrease in interplanar spacing leads to an increase in the number of diffraction satellites and a redistribution of diffracted radiation between them.

Multiple‐Edge Anomalous Diffraction (MEAD) has been applied to various quaternary sulfosalts belonging to the adamantine compound family in order to validate the distribution of copper, zinc and iron cations in the structure. Semiconductors from this group of materials are promising candidates for photovoltaic applications. Their properties strongly depend on point defects, in particular related to cation order–disorder. However, Cu+, Zn2+ and Fe2+ have very similar scattering factors and are all but indistinguishable in usual X‐ray diffraction experiments. Anomalous diffraction utilizes the dependency of the atomic scattering factors f′ and f′′ of the energy of the radiation, especially close to the element‐specific absorption edges. In the MEAD technique, individual Bragg peaks are tracked over an absorption edge. The intensity changes depending on the structure factor can be highly characteristic for Miller indices selected for a specific structural problem, but require very exact measurements. Beamline KMC‐2 at synchrotron BESSY II, Berlin, has been recently upgraded for this technique. Anomalous X‐ray powder diffraction and XAFS compliment the data. Application of this technique confirmed established cation distribution in Cu2ZnSnSe4 (CZTSe) and Cu2FeSnS4 (CFTS). In contrast to the literature, cation distribution in Cu2ZnSiSe4 (CZSiSe) is shown to adopt a highly ordered wurtz‐kesterite structure type., Multiple‐Edge Anomalous Diffraction (MEAD) has been applied to various quaternary sulfosalts belonging to the adamantine compound family in order to validate the distribution of copper, zinc and iron cations in the structure. Application of this technique confirms established cation distribution in Cu2ZnSnSe4 (CZTSe) and Cu2FeSnS4 (CFTS), but in Cu2ZnSiSe4 (CZSiSe) the cation distribution is shown to adopt a highly ordered wurtz‐kesterite structure type in contrast to the literature. image

Multiple-Edge Anomalous Diffraction (MEAD) has been applied to various quaternary sulfosalts belonging to the adamantine compound family in order to validate the distribution of copper, zinc and iron cations in the structure. Semiconductors from this group of materials are promising candidates for photovoltaic applications. Their properties strongly depend on point defects, in particular related to cation order-disorder. However, Cu

Supported PtCu/C electrocatalysts containing core–shell bimetallic PtCu nanoparticles were synthesized by sequential chemical reduction of Cu2+ and Pt(IV) in a carbon suspension, prepared on the basis of ethylene glycol–water solvent, and then treated at different temperatures in the range from 250 to 350 °C. The structural characterization of “as-prepared” PtCu nanoparticles and of those obtained after the thermal treatments was performed by transmission electron microscopy, X-ray diffraction, and Pt L3- and Cu K-edge extended X-ray absorption fine structure spectroscopy. The atomic cluster models of PtCu nanoparticles before and after the thermal treatment, reflecting the character of the components’ distribution, were generated. The electrochemical performance of the obtained PtCu/C electrocatalysts in oxygen reduction reaction was studied by cycling and linear voltammetry.

A myriad of shapes are found in biological tissues, often naturally evolved to fulfill a particular function. In the field of tissue engineering, substrate geometry influences cell behavior and tissue formation in vitro, yet little is known how this translates to an in vivo scenario. Here we investigate scaffold curvature-induced tissue growth, without additional growth factors or cells, in an ovine animal model. We show that soft tissue formation follows a curvature-driven tissue growth model. The highly organized endogenous soft matrix, potentially under mechanical strain, leads to a non-standard form of biomineralization, whereby the pre-existing organic matrix is mineralized without collagen remodeling and without an intermediate cartilage ossification phase. Micro- and nanoscale characterization of the tissue microstructure using histology, backscattered electron (BSE) and second-harmonic generation (SHG) imaging and synchrotron small angle X-ray scattering (SAXS) revealed (i) continuous collagen fibers across the soft-hard tissue interface on the tip of mineralized cones, and (ii) bone remodeling by basic multicellular units (BMUs) in regions adjacent to the native cortical bone. Thus, features of soft tissue-to-bone interface resembling the insertion sites of ligaments and tendons into bone were created, using a scaffold that did not mimic the structural or biological gradients across such a complex interface at its mature state. This study provides fundamental knowledge for biomimetic scaffold design in the fields of bone regeneration and soft tissue-to-bone interface tissue engineering. Statement of significance Geometry influences cell behavior and tissue formation in vitro. However, little is known how this translates to an in vivo scenario. Here we investigate the influence of scaffold mean surface curvature on in vivo tissue growth using an ovine animal model. Based on a multiscale tissue microstructure characterization, we show a seamless integration of soft tissue into newly formed bone, resembling the insertion sites of ligaments and tendons into bone. This interface was created using a scaffold without additional growth factors or cells that did not recapitulate the structural or biological gradients across such a complex tissue interface at its mature state. These findings have important implications for biomimetic scaffold design for bone regeneration and soft tissue-to-bone interface tissue engineering.

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. The surface acoustic waves create a dynamical diffraction grating on the crystal surface, which can be used for space–time modulation of an X-ray beam., X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space–time modulation of an X-ray beam.

Composite metal-carbon electrocatalysts PtCu/C containing core-shell bimetallic PtCu nanoparticles were synthesized by sequential chemical reduction of Cu (II) and Pt (IV) in carbon suspension, prepared on the basis of ethylene glycol–water solvent. The characterization of “as prepared” and obtained after the acid treatment PtCu nanoparticles was performed by TEM, XRD, Pt L 3 - and Cu K -edge extended X-ray absorption fine structures (EXAFS). The technique and computational code were proposed for visualization of components distribution over the volume of cluster, which represents the mean bimetallic nanoparticle, according to the values of structural parameters derived from EXAFS. By this technique, the cluster models of PtCu nanoparticles before and after acid treatment, reflecting the character of components’ distribution, were generated. The study of electrochemical performances of the obtained PtCu/C electrocatalyst revealed the similar oxygen reduction reaction (ORR) activity and increased durability compared to commercial Pt/C electrocatalyst E-TEK 20.

An erratum is presented to correct the typographical errors concerning the composition of the multilayer used in the experiment in Opt. Lett. 42, 1915.

Nanocatalysts PtAg/C with different distributions of components in bimetallic PtAg nanoparticles were synthesized by the methods of simultaneous and sequential reduction of Ag+ and Pt(IV) in carbon suspension, prepared on the basis of ethylene glycol–water solvent. The characterization of atomic structure of as prepared PtAg nanoparticles and PtAg nanoparticles obtained after acid treatment at 90 °C was performed by Pt L3-edge extended X-ray absorption fine structure (EXAFS) using the technique for determining local structure parameters of the absorbing Pt atoms, which have the nearest surrounding consisting of Pt and Ag atoms. This technique enabled stable and unambiguous values of parameters for the local structure of Pt atoms in PtAg nanoparticles to be obtained under severe correlations between some of these parameters. The effects of averaging over the sizes and compositions of PtAg nanoparticles on the obtained values of structural parameters were studied by the method of cluster simulations. Analys...

The gate opening mechanism in the highly flexible MOF Ni2 2,6 ndc 2dabco DUT 8 Ni , DUT Dresden University of Technology with unprecedented unit cell volume change was elucidated in detail using combined single crystal X ray diffraction, in situ XRD and EXAFS techniques. The analysis of the crystal structures of closed pore cp and large pore lp phases reveals a drastic and unique unit cell volume expansion of up to 254 , caused by adsorption of gases, surpassing other gas pressure switchable MOFs significantly. To a certain extent, the structural deformation is specific for the guest molecule triggering the transformation due to subtle differences in adsorption enthalpy, shape, and kinetic diameter of the guest. Combined adsorption and powder diffraction experiments using nitrogen 77 K , carbon dioxide 195 K , and n butane 272.5 K as a probe molecules reveal a one step structural transformation from cp to lp. In contrast, adsorption of ethane 185 K or ethylene 169 K results in a two step transformation with the formation of intermediate phases. In situ EXAFS during nitrogen adsorption was used for the first time to monitor the local coordination geometry of the metal atoms during the structural transformation in flexible MOFs revealing a unique local deformation of the nickel based paddle wheel node

Nickel-based superalloys are the materials of choice in the hot section of current gas turbines, but they are reaching temperature limits constrained by their melting temperature range. Co–Re alloy development was prompted by a search for new materials for future gas turbines, where the temperature of application will be considerably higher. Addition of the very high melting point refractory metal Re to Co can increase the melting range of Co alloys to much higher temperatures than the commercial Co alloys in use today. The alloy development strategy is first discussed very briefly. In this program, model ternary and quaternary compositions were studied in order to develop a basic understanding of the alloy system. In situ neutron and synchrotron measurements (small and wide angle) at high temperatures were extensively used for this purpose and some selected results from the in situ measurements are presented. In particular, the effect of boron doping in Co–Re–Cr alloys and the stability of the TaC precipitates at high temperatures were investigated. A fine dispersion of TaC precipitates strengthens some Co–Re alloys, and their stability at the application temperature is critical for the long-term creep properties.

A fundamental knowledge and understanding of the adhesion behaviour of metal–polymer systems is important as interface failure leads to a complete breakdown of flexible devices. A combination of in situ atomic force microscopy for studying topological changes and in situ synchrotron based stress measurements both during film tensile testing were used to estimate the adhesion energy of a thin bilayer film. The film systems consisted of 50–200 nm Cu with a 10 nm Cr adhesion layer on 50 μm thick polyimide. If the Cu film thickness is decreased to 50 nm the Cr interlayer starts dominating the system behaviour. An apparent transition from plastic to predominantly brittle deformation behaviour of the Cu can be observed. Then, compressive stresses in the transverse direction are high enough to cause delamination and buckling of the Cr interlayer from the substrate. This opens a new route to induce buckling of a brittle interlayer between a ductile film and a compliant substrate which is used to determine the int...

The Al-MOF CAU-13 ([Al(OH)(trans-CDC)]; trans-H2CDC = trans-1,4-cyclohexanedicarboxylic acid) is structurally related to the MIL-53 compounds that are well-known for their "breathing" behavior, i.e., the framework flexibility upon external stimuli such as the presence of adsorbate molecules. The adsorption properties of CAU-13 were investigated in detail. The sorption isotherms of N2, H2, CH4, CO, CO2, and water were recorded, and the adsorption enthalpies for the gases were determined by microcalorimetry. The structural changes upon adsorption of CO2 were followed with in situ synchrotron powder X-ray diffraction (PXRD). The patterns were analyzed by parametric unit cell refinement, and the preferential arrangement of the CO2 molecules was modeled by density functional theory calculations. The adsorption and separation of mixtures of o-, m-, and p-xylene from mesitylene showed a preferred adsorption of o-xylene. The structures of o/m/p-xylene-loaded CAU-13 were determined from PXRD data. The adsorption of xylene isomers induces a larger pore opening than that in the thermal activation of CAU-13. In the crystal structure of the activated sample CAU-13(empty pore), half of the linkers adopt the a,a confirmation and the other half the e,e conformation, and the presence of a,a-CDC(2-) ions hampers the structural flexibility of CAU-13. However, after the adsorption of xylene, all linkers are present in the e,e conformation, allowing for a wider pore opening by this new type of "breathing".

A new instrumentation for in situ X-ray powder diffraction allows to follow structural changes in the crystal structure of flexible coordination polymers during adsorption and desorption of gases. The system is based on closed cycle He-cryostat that ensures the high temperature stability in the range of 5.5–450 K. The automated gas dosing system facilitates the physisorption measurements in the pressure range of 0.01–130 kPa. The system is implemented on KMC-2 and MAGS beamlines at Helmholtz Zentrum Berlin fur Materialien und Energie. Using new instrumentation, the adsorption of CO2 and n-butane at 273 K on a flexible two-dimensional coordination polymer ELM-11 (ELM – Elastic Layer Material) was investigated.

Substantial recovery (decrease) of electrical resistance during and after unloading is demonstrated for copper films on polyethylene terephthalate substrates subjected to a tensile strain with different peak values. Particularly, the films strained to 5% exhibit full resistance recovery after unloading despite clearly visible plastic deformation of the film. The recovery of electrical resistance in connection with the mechanical behavior of film/substrate couple is discussed with the help of in situ scanning electron microscopy and X-ray diffraction analysis.

DPDAK is a software for simple and fast on- and offline reduction and analysis of X-ray scattering data. It is an open-source software with a plug-in structure allowing tailored extensions., X-ray scattering experiments at synchrotron sources are characterized by large and constantly increasing amounts of data. The great number of files generated during a synchrotron experiment is often a limiting factor in the analysis of the data, since appropriate software is rarely available to perform fast and tailored data processing. Furthermore, it is often necessary to perform online data reduction and analysis during the experiment in order to interactively optimize experimental design. This article presents an open-source software package developed to process large amounts of data from synchrotron scattering experiments. These data reduction processes involve calibration and correction of raw data, one- or two-dimensional integration, as well as fitting and further analysis of the data, including the extraction of certain parameters. The software, DPDAK (directly programmable data analysis kit), is based on a plug-in structure and allows individual extension in accordance with the requirements of the user. The article demonstrates the use of DPDAK for on- and offline analysis of scanning small-angle X-ray scattering (SAXS) data on biological samples and microfluidic systems, as well as for a comprehensive analysis of grazing-incidence SAXS data. In addition to a comparison with existing software packages, the structure of DPDAK and the possibilities and limitations are discussed.

In this work Fe–N–C catalysts were prepared by the oxalate-supported pyrolysis of FeTMPPCl or H2TMPP either in the presence or absence of sulfur. The well-known enhancing effect of sulfur-addition on the oxygen reduction activity was confirmed for these porphyrin precursors. The pyrolysis process was monitored in situ by high-temperature X-ray diffraction under synchrotron radiation (HT-XRD) and thermogravimetry coupled with mass-spectroscopy (TG-MS). It was found that the beneficial effect of sulfur could be attributed to the prevention of iron-carbide formation during the heat-treatment process. In the case of pyrolysis of the sulfur-free precursors an excessive iron-carbide formation leads to disintegration of FeN4-centers, hence limiting the number of ORR active sites on the final catalyst. Physical characterization of the catalysts by bulk elemental analysis, X-ray diffraction (XRD), Raman and 57Fe Mosbauer spectroscopy confirmed the outcome from HT-XRD and TG-MS. It could be shown that the avoidance of carbide formation during pyrolysis represents a promising way to enhance the density of ORR active sites on those catalysts. This can be done either by sulfur-addition or the performance of an intermediate acid leaching. As iron carbide is often found as a by-product in the preparation of Fe–N–C catalysts this work gives some general strategies for enhancing the density of active sites enabling higher current densities.

Capillary optics are used for X-ray fluorescence micro-analysis using the Cu Kα line provided by a rotating anode. The excitation beam is focused using a polycapillary lens on a Co–Ti sample. Cylindrical glass capillaries of various diameters are fitted to the X-ray detector (Energy Dispersive X-Ray (EDX) analyzer) and displaced along the irradiated zone of the sample. The fluorescence is studied as a function of capillary position. Good agreement is found between experimental and calculated lateral widths of the fluorescence collection, taken into account the cylindrical capillary critical angles relevant in the experiment. The influence of the cylindrical capillary diameter on the signal level detected is studied to estimate the possibility of lateral resolution increase of X-ray fluorescence technique both in-lab and in synchrotron environment. Copyright © 2013 John Wiley & Sons, Ltd.

A five-component crystal of the lanthanum–gallium silicate family Ca3TaGa3Si2O14 (CTGS) was grown by the Czochralski method. The CTGS crystal, like the langasite crystal (La3Ga5SiO14, LGS), possesses unique temperature properties and the fewer number of the Ga atoms in the unit cell makes the density much lower and, consequently, increases the velocity of acoustic wave propagation. The unit-cell parameters were determined by the powder diffraction technique. The defects in the CTGS crystal structure were studied by X-ray topography, which enables the visualization of growth banding characteristics of crystals grown by the Czochralski method. Surface acoustic wave (SAW) propagation in the CTGS crystal was investigated by the high-resolution X-ray diffraction method on the BESSY II synchrotron radiation source. The velocities of propagation and power flow angles of SAWs in the Y- and X-cuts of the CTGS crystal were determined from the X-ray diffraction spectra.

Ni:a-C:H thin films obtained by reactive sputtering processes were investigated using EXAFS and subsequent wavelet analysis. Depending on overall thin film deposition conditions, the clusters of Ni in Ni:a-C:H can appear as fcc-Ni or as a non-fcc-Ni phase, such as hcp-Ni or Ni3C. While hcp-Ni and Ni3C are hardly distinguishable by XRD, the EXAFS analysis can reveal if carbon is the nearest neighbour of Ni or not, thus if Ni3C is present or hcp-Ni. Our study showed that wavelet transformation analysis of the EXAFS data is necessary to discriminate clearly between hcp-Ni and Ni3C regarding the presence or absence of carbon coordination shells around the X-ray absorbing Ni atoms. Furthermore, we are confident to have identified Ni3C in our thin films, however, we cannot exclude the possibility of the co-existence of hcp-Ni. Finally, calculations of XRD peaks of hcp-Ni and Ni3C showed that a discrimination of these two crystal phases might be feasible when the crystallite size is increased beyond 40 nm.

Dentin in teeth is a bone-like nanocomposite built of carbonated hydroxyapatite (cHAP) mineral particles, protein and water that does not remodel nor heal. It is assumed to be excellently adapted for decades of mechanical function, due to the interplay between its constituents. Using samples of human origin, we combine heat treatments with synchrotron X-ray diffraction, second-harmonic generation microscopy, Raman spectroscopy, and phase contrast-enhanced nano-tomography to study the water-assisted functional coupling of the biocomposite components. Across roots we find a gradual reduction in the c-lattice parameter of the cHAP nano-crystals, from 6.894 Å externally down to 6.885 Å in deeper tooth regions. Here, approaching the pulp, tissue is formed at later stages of tooth development. In all regions, a compressive strain of ~0.3 % is observed upon drying by mild heating (125 ºC). Dehydration results in a substantial increase in the averaged microstrain fluctuations in the mineral nanoparticles. The mineral crystallite platelet lengths fall off from ~36 nm externally to ~26 nm closer to the pulp. Our results suggest that both morphology and mineral-collagen coupling allow mineral nano-particles in dentin to sustain rather large stresses of 300 MPa, far exceeding mastication stresses, and that such loads are sustained through durable collagen fibril contractions.

Ca3NbGa3Si2O14 (CNGS), a five-component crystal of lanthanum-gallium silicate group, was grown by the Czochralski method. The parameters of the elementary unit cell of the crystal were measured by powder diffraction. The independent piezoelectric strain coefficients $$d{}_{11}$$ and $$d_{14}$$ were determined by the triple-axis X-ray diffraction in the Bragg and Laue geometries. Excitation and propagation of surface acoustic waves (SAW) were studied by high-resolution X-ray diffraction at BESSY II synchrotron radiation source. The velocity of SAW propagation and power flow angles in the $$Y$$ -, $$X$$ - and $$yxl/{+}36^\circ$$ -cuts of the CNGS crystal were determined from the analysis of the diffraction spectra. The CNGS crystal was found practically isotropic by its acoustic properties.

Recent studies of Parkinson's disease indicate that dorsal motor nucleus of nerve vagus is one of the earliest brain areas affected by alpha-synuclein and Lewy bodies pathology. The influence of electrical stimulation of vagus nerve on elemental composition of dopamine related brain structures in rats is investigated. Synchrotron radiation based X-ray fluorescence was applied to the elemental micro-imaging and quantification in thin tissue sections. It was found that elements such as P, S, Cl, K, Ca, Fe, Cu, Zn, Se, Br and Rb are present in motor cortex, corpus striatum, nucleus accumbens, substantia nigra, ventral tectal area, and dorsal motor nucleus of vagus. The topographic analysis shows that macro-elements like P, S, Cl and K are highly concentrated within the fiber bundles of corpus striatum. In contrast the levels of trace elements like Fe and Zn are the lowest in these structures. It was found that statistically significant differences between the animals with electrical stimulation of vagus nerve and the control are observed in the left side of corpus striatum for P (p = 0.04), S (p = 0.02), Cl (p = 0.05), K (p = 0.02), Fe (p = 0.04) and Zn (p = 0.02). The mass fractions of these elements are increased in the group for which the electrical stimulation of vagus nerve was performed. Moreover, the contents of Ca (p = 0.02), Zn (p = 0.07) and Rb (p = 0.04) in substantia nigra of right hemisphere are found to be significantly lower in the group with stimulation of vagus nerve than in the control rats.

The 3D shape of X-ray reflections from the γ/γ′-microstructure of a nickel-base superalloy was investigated using synchrotron X-ray radiation and a position sensitive area detector. The measurements were performed on the 4th generation single-crystal nickel-base superalloy TMS138. The results show that X-ray reflections from non-cubic crystallographic planes have a complex 3D shape which changes during rafting. The 3D intensity distributions contain information about the spacing of the planes and their orientation as well. Whereas h00 reflections show the usual splitting into a γ′ and one γ-subreflection, the hh0 and hhh reflections show two and three γ-peaks respectively, resulting from the different types of {100} matrix channels. Therefore, these 3D diffraction measurements supply additional information about the spatial distribution of microstrains.

Decomposition during constant heating of as-received and pre-oxidized titanium hydride (TiH 2 ) powder under flowing and stationary Ar was studied in situ by synchrotron X-ray and neutron diffraction. Diffraction data were compared to corresponding thermoanalysis traces in order to relate peaks of H 2 release with individual phase transformations. We found that every peak of H 2 release is correlated with regimes of lattice parameter contraction. Core–shell models to describe the decomposition processes measured were found, and further verified by electron microscopy. The models show that a shell of the hexagonal close-packed hydrogen solid solution (α) around each particle core controls its dehydrogenation for as-received TiH 2 , while a TiO 2 rutile shell controls the outgassing from the pre-oxidized powder.

The results of investigations of solar grade mc-Si by means of combination of scanning X-ray beam excited optical luminescence microscopy (SXEOL), X-ray beam induced current (XBIC) and X-ray fluorescence (XRF) are presented. It was found, that for relatively clean sample SXEOL and XBIC provide similar information about the recombination activity of defects while for the samples with a high transition metal content there are significant differences in the provided information. The reasons of the revealed XBIC - SXEOL differences are discussed.

The fracturing behavior of polymers and polymeric composites is of great interest in the scientific and application community. Especially in the case of silicate-layered nanocomposites the influence of fillers on the fracturing behavior is still fairly unclear. Fractures of semicrystalline polymers are accompanied by various processes of which shearing and cavitations are the most common ones. Nanocomposite deformation due to the delamination of fillers seems to be the most practical way leading to fractures with relatively low strains. With the method of scanning small angle X-ray scattering (SAXS) and wide angle X-ray diffraction (WAXD) it is possible to combine information on the structural details with the position on the sample, with the actual position resolution of the investigation being defined by the size of the X-ray beam used to scan the sample. By means of the application of synchrotron radiation it is nowadays possible to adjust the actual beam size to the dimensions of the region of interest, which is why it is an adequate tool for studying the deformation region near a crack tip. In a native polypropylene sample, the fracturing process was accompanied by shear yielding as well as lamellae fragmentation and reorienting. In the highly deformed material near the crack tip fibrillated material could be found. However, in the polymeric nanocomposites (PNC) shearing, lamellae fragmentation, and fibrillation were hindered by the filler due to which the material did not have so much freedom to dissipate energy and fractures occurred much earlier. In this paper the comparison of a PNC and its native polymer is to provide an overview of the different deformation mechanism and the structural details around the crack tip.

In X-ray beam induced current (XBIC) in combination with X-ray fluorescence (XRF) and X-ray absorption (XAS) microscopy techniques is now widely used as a powerful tool for the investigation of transition metal (TM) behavior in Si. The aim of this work was to replace XBIC with a new recombination-sensitive, but contactless technique, that is, scanning X-ray beam excited optical luminescence microscopy (μ-SXEOL). We report for the first time the successful realization of μ-SXEOL to register the spatial distribution of band-band luminescence in silicon in a reasonable time of 1 s/pixel with X-ray flux of 10 11 /s. Results of simultaneous μ-SXEOL/XBIC/ μ-XRF measurements on multi-crystalline silicon are presented. A correlation between XBIC and μ-SXEOL maps of the same sample as well as significant differences are found. The magnitude of μ-SXEOL signal is shown to anti-correlate with the averaged amount of copper detected by μ-XRF.

We investigate the potential of large-scale diffractive-refractive normal-incidence transmission lenses for the development of space-based hard x-ray telescopes with an angular resolution in the range of (10-6-10-3) arcsec over a field of view that is restricted by the available detector size. Coherently stepped achromatic lenses with diameters up to 5 m for compact apertures and 13 m in the case of segmentation provide an access to spectrally resolved imaging within keV-wide bands around the design energy between 10 and 30 keV. Within an integration time of 106 s, a photon-limited 5σ sensitivity down to (10-9-10-7) s-1 cm-2 keV-1 can be achieved depending on the specific design. An appropriate fabrication strategy, feasible nowadays with micro-optical technologies, is considered and relies on the availability of high-purity carbon or polymer membranes. X-ray fluorescence measurements of various commercially available carbon-based materials prove for most of them the existence of a virtually negligible contamination by critical trace elements such as transition metals on the ppm level.

The stability of the microstructure at high temperatures was studied in an experimental Co–Re-based alloy. The experimental alloy is mainly strengthened by Cr-carbides, particularly by those in the form of thin lamellar plates. Electron microscopic investigation on samples exposed for up to 1 000 h to temperatures of 1 000 and 1 200 °C showed that Cr23C6 type carbides present in the alloy in different morphologies are unstable at these temperatures. It was also observed that the alloy hardness dropped after exposing the samples to elevated temperatures and much of this loss occurred within the first 100 h. In-situ diffraction measurements with synchrotron radiation showed that carbide dissolution started as early as 3 h of holding at 1 000 °C. Moreover, in-situ small angle neutron scattering results indicated that the carbides at the grain boundaries and the blocky carbides dissolve first and then the thin lamellar carbides. Further, the enrichment of Cr in the Co-matrix phase, which took place due to the dissolution of Cr-carbides, stabilized a Cr–Re-rich σ phase. Although the dissolution of lamellar carbides results in a significant loss of strength, the formation of σ phase with extremely high hardness partly compensated the for loss. The σ phase is stable even at 1 200 °C.

Helium-atomized amorphous Al85Ni10La5 (at.%) powder was investigated in the as-atomized state and after consolidation at room temperature using high pressure torsion. The samples were investigated by scanning electron microscopy, in situ and ex situ angle-dispersive X-ray diffractometry (XRD), ex situ energy-dispersive XRD, differential scanning calorimetry, and inductively coupled plasma mass spectroscopy. The as-atomized powder shows a glass transition and subsequent crystallization of fcc-Al and intermetallic phases within a narrow temperature range upon continuous heating. Primary crystallization of fcc-Al occurs during isothermal heating below the crystallization temperature. After consolidation, no glass transition occurs upon continuous heating. XRD of consolidated disc-shape samples reveal fcc-Al crystals within the residual amorphous matrix. The amount of fcc-Al crystals increases with plastic shear deformation along the disc radius and with rotation angle. The results indicate that the primary precipitation of fcc-Al is strain-induced and possibly athermal.