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Abstract In this study, we introduce a method designed to eliminate parallax artefacts present in X-ray powder diffraction computed tomography data acquired from large samples. These parallax artefacts manifest as artificial peak shifting, broadening and splitting, leading to inaccurate physicochemical information, such as lattice parameters and crystallite sizes. Our approach integrates a 3D artificial neural network architecture with a forward projector that accounts for the experimental geometry and sample thickness. It is a self-supervised tomographic volume reconstruction approach designed to be chemistry-agnostic, eliminating the need for prior knowledge of the sample’s chemical composition. We showcase the efficacy of this method through its application on both simulated and experimental X-ray powder diffraction tomography data, acquired from a phantom sample and an NMC532 cylindrical lithium-ion battery.

We studied the short-range order and the atomic dynamics of stable and undercooled binary Zr2Co alloy melts as well as their density and viscosity. The containerless processing technique of electrostatic levitation was used to achieve deep undercooling and to avoid contaminations. Static structure factors are determined by combining this technique with neutron and high energy X-ray diffraction. Co self-diffusion coefficients are measured by quasielastic neutron scattering. Our results reveal that the short-range order of the Zr2Co melts closely resembles that previously observed for Zr64Ni36. We consider this as the origin of the very similar melt dynamics of these two alloys at same temperatures. On the other hand, the difference in the structure and dynamics when compared with those of Zr2Cu and Zr2Pd shows clearly that not only the atomic sizes, but also electronic properties or chemical bonding have an important influence on the melt properties of Zr-based glass forming melts.PACS number(s): 61.20.−p, 61.25.Mv, 66.30.Fq, 61.05.F-, 61.05.cp

Magnetic field induced competing phases in high-temperature superconductors provide a testbed for various theoretical scenarios. Here, Choi et al. report evidence of inhomogeneous superconducting state due to the different competition strength between two charge density wave orders in YBa2Cu3O6.67.

X-ray Diffraction Computed Tomography (XRD-CT) represents a cutting-edge method for non-destructive material analysis, offering the unique capability of providing molecular-level information with spatial resolution. In this study, we have applied XRD-CT to investigate pharmaceutically relevant tablets that have been subjected to a range of compression pressures typical in tablet manufacturing. By employing XRD-CT to pharmaceutical tablets, we reveal material changes without tablet destruction, thereby avoiding potential phase transformations during sample preparation that could lead to errors in the interpretation of the processes that have occurred. Utilizing a pressure-sensitive marker, glycolide, we have tracked changes within tablet structures induced by compression, pinpointing locations where glycolide undergoes pressure-induced transformation. Additionally, we conducted a follow-up study with analysis one month later, observing an in situ hydrolysis reaction of glycolide within the tablets. Through the complementary use of electron diffraction, we have elucidated the structure of the hydrolysis product, further enhancing our understanding of temporal changes in the tablets., (© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The discovery of unconventional superconductivity often triggers significant interest in associated electronic and structural symmetry breaking phenomena. For the infinite-layer nickelates, structural allotropes are investigated intensively. Here, using high-energy grazing-incidence x-ray diffraction, we demonstrate how in-situ temperature annealing of the infinite-layer nickelate PrNiO 2+ x ( x  ≈ 0) induces a giant superlattice structure. The annealing effect has a maximum well above room temperature. By covering a large scattering volume, we show a rare period-six in-plane (bi-axial) symmetry and a period-four symmetry in the out-of-plane direction. This giant unit-cell superstructure-likely stemming from ordering of diffusive oxygen-persists over a large temperature range and can be quenched. As such, the stability and controlled annealing process leading to the formation of this superlattice structure provides a pathway for novel nickelate chemistry., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2025.)

Stomatopods are ferocious hunters that use weaponized appendages to strike down their pray. The clubs of species such as Odontodactylus scyllarus undergo tremendous forces, and in consequence they have intricate structures, consisting of hydroxyapatite, chitin, amorphous calcium phosphate and carbonate, and occasionally calcite. These materials are distributed differently across the four major zones of the dactyl club: the impact, periodic lateral and medial, and striated regions. While stomatopod clubs and their structure have been studied for a long time, studies have thus far been constrained to 2D mapping experiments with moderate resolution due to difficulties in preparing whole club thin sections, and absorption tomography that gives information on densities but not molecular length scales. To address this problem, and shed light on the structure of entire clubs, we herein used X-ray powder diffraction computed tomography (XRD-CT) using high energy X-rays at the P07 beamline of PETRA-III to allow penetrating the large samples whilst still obtaining high resolution information. This allowed mapping the 3D distribution of diffraction phases including the biomineral apatite and the semi-crystal chitin matrix. This showed that hydroxyapatite forms an envelope around the club, and that chitin forms 2D sheets in the periodic region of the club., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Colloidal lead halide perovskite nanocrystals have potential for lighting applications due to their optical properties. Precise control of the nanocrystal dimensions and composition is a prerequisite for establishing practical applications. However, the rapid nature of their synthesis precludes a detailed understanding of the synthetic pathways, thereby limiting the optimisation. Here, we deduce the formation mechanisms of anisotropic lead halide perovskite nanocrystals, 1D nanorods and 2D nanoplatelets, by combining in situ X-ray scattering and photoluminescence spectroscopy. In both cases, emissive prolate nanoclusters form when the two precursor solutions are mixed. The ensuing antisolvent addition induces the divergent anisotropy: The intermediate nanoclusters are driven into a dense hexagonal mesophase, fusing to form nanorods. Contrastingly, nanoplatelets grow freely dispersed from dissolving nanoclusters, stacking subsequently in lamellar superstructures. Shape and size control of the nanocrystals are determined primarily by the antisolvent's dipole moment and Hansen hydrogen bonding parameter. Exploiting the interplay of antisolvent and organic ligands could enable more complex nanocrystal geometries in the future., (© 2024. The Author(s).)

Nanocrystal self-assembly into supercrystals provides a versatile platform for creating novel materials and devices with tailored properties. While common self-assembly strategies imply the use of purified nanoparticles after synthesis, conversion of chemical precursors directly into nanocrystals and then supercrystals in simple procedures has been rarely reported. Here, the nucleation and growth of CuPd icosahedra and their consecutive assembly into large closed-packed face-centered cubic (fcc) supercrystals are studied. To this end, the study simultaneously and in situ measures X-ray total scattering with pair distribution function analysis (TS-PDF) and small-angle X-ray scattering (SAXS). It is found that the supercrystals' formation is preceded by an intermediate dense phase of nanocrystals displaying short-range order (SRO). It is further shown that the organization of oleic acid/oleylamine surfactants into lamellar structures likely drives the emergence of the SRO phase and later of the supercrystals by reducing the volume accessible to particle diffusion. The supercrystals' formation as well as their disassembly are triggered by temperature. The study demonstrates that ordering of solvent molecules can be crucial in the direct synthesis of supercrystals. The study also provides a general approach to investigate novel preparation routes of supercrystals in situ and across several length scales via X-ray scattering., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

CuBi 2 O 4 has recently emerged as a promising photocathode for photo-electrochemical (PEC) water splitting. However, its fast degradation under operation currently poses a limit to its application. Here, we report a novel method to study operando the semiconductor-electrolyte interface during PEC operation by surface-sensitive high-energy X-ray scattering. We find that a fast decrease in the generated photocurrents correlates directly with the formation of a metallic Bi phase. We further show that the slower formation of metallic Cu, as well as the dissolution of the electrode in contact with the electrolyte, further affect the CuBi 2 O 4 activity and morphology. Our study provides a comprehensive picture of the degradation mechanisms affecting CuBi 2 O 4 electrodes under operation and poses the methodological basis to investigate the photocorrosion processes affecting a wide range of PEC materials., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

New diagnostic approaches are needed to drive progress in the field of electrocatalysis and address the challenges of developing electrocatalytic materials with superior activity, selectivity, and stability. To this end, we developed a versatile experimental setup that combines two complementary in-situ techniques for the simultaneous chemical and structural analysis of planar electrodes under electrochemical conditions: high-energy surface X-ray diffraction (HE-SXRD) and infrared reflection absorption spectroscopy (IRRAS). We tested the potential of the experimental setup by performing a model study in which we investigated the oxidation of preadsorbed CO on a Pt(111) surface as well as the oxidation of the Pt(111) electrode itself. In a single experiment, we were able to identify the adsorbates, their potential dependent adsorption geometries, the effect of the adsorbates on the surface morphology, and the structural evolution of Pt(111) during surface electro-oxidation. In a broader perspective, the combined setup has a high application potential in the field of energy conversion and storage.

The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure, induced by the necessarily high energy of short-wavelength radiation. Imaging the inelastically scattered X-rays at a photon energy of 60 keV (0.02 nm wavelength) offers greater signal per energy transferred to the sample than coherent-scattering techniques such as phase-contrast microscopy and projection holography. We present images of dried, unstained, and unfixed biological objects obtained by scanning Compton X-ray microscopy, at a resolution of about 70 nm. This microscope was realised using novel wedged multilayer Laue lenses that were fabricated to sub-ångström precision, a new wavefront measurement scheme for hard X rays, and efficient pixel-array detectors. The doses required to form these images were as little as 0.02% of the tolerable dose and 0.05% of that needed for phase-contrast imaging at similar resolution using 17 keV photon energy. The images obtained provide a quantitative map of the projected mass density in the sample, as confirmed by imaging a silicon wedge. Based on these results, we find that it should be possible to obtain radiation damage-free images of biological samples at a resolution below 10 nm., (© 2023. The Author(s).)

In heterogeneous catalysis, operando measurements probe catalysts in their active state and are essential for revealing complex catalyst structure-activity relationships. The development of appropriate operando sample environments for spatially resolved studies has come strongly into focus in recent years, particularly when coupled to the powerful and multimodal characterization tools available at synchrotron light sources. However, most catalysis studies at synchrotron facilities only measure structural information about the catalyst in a spatially resolved manner, whereas gas analysis is restricted to the reactor outlet. Here, a fully automated and integrated catalytic profile reactor setup is shown for the combined measurement of temperature, gas composition and high-energy X-ray diffraction (XRD) profiles, using the oxidative dehydrogenation of C 2 H 6 to C 2 H 4 over MoO 3 /γ-Al 2 O 3 as a test system. The profile reactor methodology was previously developed for X-ray absorption spectroscopy and is here extended for operando XRD. The profile reactor is a versatile and accessible research tool for combined spatially resolved structure-activity profiling, enabling the use of multiple synchrotron-based characterization methods to promote a knowledge-based optimization of a wide range of catalytic systems in a time- and resource-efficient way., (open access.)

Understanding the nucleation and growth mechanisms of nanocrystals under hydro- and solvothermal conditions is key to tailoring functional nanomaterials. High-energy and high-flux synchrotron radiation is ideal for characterization by powder X-ray diffraction and X-ray total scattering in real time. Different versions of batch-type cell reactors have been employed in this work, exploiting the robustness of polyimide-coated fused quartz tubes with an inner diameter of 0.7 mm, as they can withstand pressures up to 250 bar and temperatures up to 723 K for several hours. Reported here are recent developments of the in situ setups available for general users on the P21.1 beamline at PETRA III and the DanMAX beamline at MAX IV to study nucleation and growth phenomena in solvothermal synthesis. It is shown that data suitable for both reciprocal-space Rietveld refinement and direct-space pair distribution function refinement can be obtained on a timescale of 4 ms., (© Martin Roelsgaard et al. 2023.)

Cardiolipin (CL) is a unique phospholipid featuring a dimeric structure. With its four alkyl chains, it has a large hydrophobic region and the charged hydrophilic head group is relatively small. Biological membranes exhibit CL exclusively in the inner bacterial and mitochondrial membranes. Alteration of CL packing can lead to structural changes and membrane instabilities. One environmental influence is the change in pH. Since the acidic properties of the phosphate head groups remain still controversial in literature, this work focusses on the influence of pH on the ionization degree of CL. For the analyses, surface pressure (π) - molecular area (A) isotherm experiments were combined with total reflection X-ray fluorescence (TRXF) and grazing incidence X-ray diffraction (GIXD). Continuous ionization with a high CL packing density was observed in the monolayer over a wide pH range. No individual pKa values can be assigned to the two phosphate groups, but mutual influence is observed., (© 2022 The Authors. ChemPhysChem published by Wiley-VCH GmbH.)

Characterizing electrode surface structures under operando conditions is essential for fully understanding structure-activity relationships in electrocatalysis. Here, we combine in a single experiment high-energy surface x-ray diffraction as a characterizing technique with a rotating disk electrode to provide steady state kinetics under electrocatalytic conditions. Using Pt(111) and Pt(100) model electrodes, we show that full crystal truncation rod measurements are readily possible up to rotation rates of 1200 rpm. Furthermore, we discuss possibilities for both potentiostatic as well as potentiodynamic measurements, demonstrating the versatility of this technique. These different modes of operation, combined with the relatively simple experimental setup, make the combined rotating disk electrode-surface x-ray diffraction experiment a powerful technique for studying surface structures under operando electrocatalytic conditions.

We report a ferroelectric order around ∼99 K ( T FE ), which is considerably above the long range ferrimagnetic order at 25 K ( T N ). The value of saturation electric polarization is considerable as ∼570 μ C m -2 for a poling field of 5 kV cm -1 . The ferroelectric order is associated with a significant magnetoelectric coupling below ∼90 K. A weak signature of T FE is observed in the dielectric constant, which is associated with a linear magnetodielectric response at 18 K(-1  K -1 is noted at T N for a change in field of 50 kOe, which involves a strong magnetoelastic coupling. The results indicate considerable structural instabilities, which is linked with the observed multifunctional properties of YbCrO 4 ., (© 2022 IOP Publishing Ltd.)

A laser heating system for samples confined in diamond anvil cells paired with in situ X-ray diffraction measurements at the Extreme Conditions Beamline of PETRA III is presented. The system features two independent laser configurations (on-axis and off-axis of the X-ray path) allowing for a broad range of experiments using different designs of diamond anvil cells. The power of the continuous laser source can be modulated for use in various pulsed laser heating or flash heating applications. An example of such an application is illustrated here on the melting curve of iron at megabar pressures. The optical path of the spectroradiometry measurements is simulated with ray-tracing methods in order to assess the level of present aberrations in the system and the results are compared with other systems, that are using simpler lens optics. Based on the ray-tracing the choice of the first achromatic lens and other aspects for accurate temperature measurements are evaluated., (open access.)

Colloidal bismuth therapeutics have been used for hundreds of years, yet remain mysterious. Here we report an X-ray pair distribution function (PDF) study of the solvolysis of bismuth disalicylate, a model for the metallodrug bismuth subsalicylate (Pepto-Bismol). This reveals catalysis by traces of water, followed by multistep cluster growth. The ratio of the two major species, {Bi 9 O 7 } and {Bi 38 O 44 }, depends on exposure to air, time, and the solvent. The solution-phase cluster structures are of significantly higher symmetry in comparison to solid-state analogues, with reduced off-center Bi 3+ displacements. This explains why such "magic-size" clusters can be both stable enough to crystallize and sufficiently labile for further growth.

Synchrotron high-energy X-ray diffraction computed tomography has been employed to investigate, for the first time, commercial cylindrical Li-ion batteries electrochemically cycled over the two cycling rates of C/2 and C/20. This technique yields maps of the crystalline components and chemical species as a cross-section of the cell with high spatiotemporal resolution (550 × 550 images with 20 × 20 × 3 µm 3 voxel size in ca. 1 h). The recently developed Direct Least-Squares Reconstruction algorithm is used to overcome the well-known parallax problem and led to accurate lattice parameter maps for the device cathode. Chemical heterogeneities are revealed at both electrodes and are attributed to uneven Li and current distributions in the cells. It is shown that this technique has the potential to become an invaluable diagnostic tool for real-world commercial batteries and for their characterization under operating conditions, leading to unique insights into "real" battery degradation mechanisms as they occur., (© 2021 The Authors. Small Methods published by Wiley-VCH GmbH.)

A combination of complementary high-energy X-ray diffraction, containerless solidification during electromagnetic levitation and transmission electron microscopy is used to map in situ the phase evolution in a prototype Cu-Zr-Al glass during flash-annealing imposed at a rate ranging from 10 2 to 10 3  K s -1 and during cooling from the liquid state. Such a combination of experimental techniques provides hitherto inaccessible insight into the phase-transformation mechanism and its kinetics with high temporal resolution over the entire temperature range of the existence of the supercooled liquid. On flash-annealing, most of the formed phases represent transient (metastable) states - they crystallographically conform to their equilibrium phases but the compositions, revealed by atom probe tomography, are different. It is only the B2 CuZr phase which is represented by its equilibrium composition, and its growth is facilitated by a kinetic mechanism of Al partitioning; Al-rich precipitates of less than 10 nm in a diameter are revealed. In this work, the kinetic and chemical conditions of the high propensity of the glass for the B2 phase formation are formulated, and the multi-technique approach can be applied to map phase transformations in other metallic-glass-forming systems.

The compounds, NiSb 2 O 6 (NSO) and MnSb 2 O 6 (MSO) attract the community for the quasi one-dimensional and layered structure composed of Ni 2+ and Mn 2+ , which orders antiferromagnetically at T N = 6.7 and 12 K, respectively. Here, we report the Griffiths-like phase much above T N in the range of 37-85 K and 25-80 K for NSO and MSO, respectively. The dc magnetization results indicate the Griffiths-like phase, following the modified Curie-Weiss law. The magneto-capacitive responses for both the compounds show anomalies at the onset of the Griffiths-like phase. Intriguingly, the low temperature synchrotron diffraction results are conclusive for determining the singularities for both the compounds. Interplay between the low-dimensionality, magnetic frustration, and magneto-elastic coupling correlates the observed short range ordered state, which is suggested as a Griffiths-like phase, above T N for both the compounds., (© 2021 IOP Publishing Ltd.)

X-ray microscopy offers the opportunity to image biological and radiosensitive materials without special sample preparations, bridging optical and electron microscopy capabilities. However, the performance of such microscopes, when imaging radiosensitive samples, is not limited by their intrinsic resolution, but by the radiation damage induced on such samples. Here, we demonstrate a novel, to the best of our knowledge, radio-efficient microscope, scanning Compton X-ray microscopy (SCXM), which uses coherently and incoherently (Compton) scattered photons to minimize the deposited energy per unit of mass for a given imaging signal. We implemented SCXM, using lenses capable of efficiently focusing 60 keV X-ray photons into the sub-micrometer scale, and probe its radio-efficient capabilities. SCXM, when implemented in high-energy diffraction-limited storage rings, e.g., European Synchrotron Radiation Facility Extremely Brilliant Source and PETRA IV, will open the opportunity to explore the nanoscale of unstained, unsectioned, and undamaged radiosensitive materials.

Details of fast-resistive-heating setups, controlled heating ranging from ∼10 1 K s -1 to ∼10 3 K s -1 , to study in situ phase transformations (on heating and on cooling) in metallic glasses by high-energy synchrotron x-ray diffraction are discussed. Both setups were designed and custom built at the Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden) and have been implemented at the P02.1 Powder Diffraction and Total Scattering Beamline and the P21.1 Swedish Materials Science Beamline at PETRA III storage ring, DESY, Hamburg. The devices are interchangeable at both beamlines. Joule heating is triggered automatically and is timed with the incident beam and detector. The crystallization process can be controlled via a feedback circuit by monitoring the change in the time-dependent resistivity and temperature of glasses. Different ambient atmospheres, such as vacuum and inert gases (He and Ar), can be used to control oxidation and cooling. The main focus of these devices is on understanding the crystallization mechanism and kinetics in metallic glasses, which are brittle and for which fast heating gives defined glass-crystal composites with enhanced plasticity. As an example, phase-transformation sequence(s) in a prototyped Cu-Zr-based metallic glass is described on heating, and a crystalline phase beneficial to the plasticity is identified.

Functional thin films are commonly integrated in electronic devices as part of a multi-layer architecture. Metal/oxide/metal structures e.g. in resistive switching memory and piezoelectric microelectrochemical devices are relevant applications. The films are mostly fabricated from the vapour phase or by solution deposition. Processing conditions with a limited thermal budget typically yield nanocrystalline or amorphous layers. For these aperiodic materials, the structure is described in terms of the local atomic order on the length scale of a few chemical bonds up to several nanometres. Previous structural studies of the short-range order in thin films have addressed the simple case of single coatings on amorphous substrates. By contrast, this work demonstrates how to probe the local structure of two stacked functional layers by means of grazing incidence total X-ray scattering and pair distribution function (PDF) analysis. The key to separating the contributions of the individual thin films is the variation of the incidence angle below the critical angle of total external reflection, In this way, structural information was obtained for functional oxides on textured electrodes, i.e. PbZr 0.53 O 0.47 O 3 on Pt[111] and HfO 2 on TiN, as well as HfO 2 -TiO x bilayers. For these systems, the transformations from disordered phases into periodic structures via thermal teatment are described. These examples highlight the opportunity to develop a detailed understanding of structural evolution during the fabrication of real thin film devices using the PDF technique.

Glass and anti-glass samples of bismuth tellurite ( x Bi 2 O 3 -(100 - x )TeO 2 ) and bismuth niobium tellurite ( x Bi 2 O 3 - x Nb 2 O 5 -(100 - 2 x )TeO 2 ) systems were prepared by melt-quenching. The bismuth tellurite system forms glasses at low Bi 2 O 3 concentration of 3 to 7 mol%. At 20 mol% Bi 2 O 3 , the glass forming ability of the Bi 2 O 3 -TeO 2 system decreases drastically and the anti-glass phase of monoclinic Bi 2 Te 4 O 11 is produced. Structures of glass and the anti-glass Bi 2 Te 4 O 11 samples were studied by high-energy X-ray diffraction, reverse Monte Carlo simulations and Rietveld Fullprof refinement. All glasses have short short-range disorder due to the existence of at least three types of Te-O bonds of lengths: 1.90, 2.25 and 2.59 Å, besides a variety of Bi-O and Nb-O bond-lengths. The medium-range order in glasses is also disturbed due to the distribution of Te-Te pair distances. The average Te-O co-ordination ( N Te-O O 2 O 3 O 2 O 5 mol% and is in the range: 4.17 to 3.56. The anti-glass Bi 2 O 4 O 11 has a long-range order of cations but it has vibrational disorder and it exhibits sharp X-ray reflections but broad vibrational bands similar to that in glasses. Anti-glass Bi 2 O 4 O 11 has an N Te-O of 2.96 and is significantly lower than in glass samples., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The structures of xSrO-(100 - x)TeO 2 (x = 5, 7.5, 8.5 and 10 mol.%) glass, anti-glass and crystalline samples were studied by high-energy X-ray diffraction (HEXRD), reverse Monte Carlo (RMC) simulations, atomic pair distribution function analysis and Fullprof Rietveld refinement. The atomic pair distributions show the first peak at 1.90 Å due to the Te-O equatorial bonds and the Te-O peak is asymmetrical due to the range of Te-O bond lengths in glass, anti-glass and crystalline samples. The short-range structural properties of glasses such as Te-O bond lengths, Te-O speciation, Te-Te distances and O-Te-O bond angle distributions were determined by RMC simulations. The average Te-O coordination number (N Te-O ) for 5SrO-95TeO 2 glass is 3.93 which decreases to 3.59 on increasing the SrO concentration to 10 mol.%. The changes in N Te-O revealed that the glass network predominantly contains TeO 4 units with a small amount of TeO 3 units and there is a structural transformation TeO 4 → TeO 3 with an increase in SrO concentration. The O-Te-O bond angle distributions have a peak at 79° and reveal that the O equatorial -Te-O equatorial bonds are the most abundant linkages in the tellurite network. Two glass samples containing 7.5 and 8.5 mol.% of SrO were annealed at 350°C for 1 h to produce anti-glass phases; they were further annealed at 450°C for 4 h to transform them into crystalline phases. The anti-glass samples are disordered cubic SrTe 5 O 11 and the disordered monoclinic SrTeO 3 phases, whereas the crystalline samples contain monoclinic SrTeO 3 and the orthorhombic TeO 2 phases. The unit-cell parameters of the anti-glass and crystalline structures were determined by Fullprof Rietveld refinement. Thermal studies found that the glass transition temperature increases with an increase in SrO mol.% and the results on the short-range structure of glasses from Raman spectroscopy are in agreement with the RMC findings.

Lipid/surfactant miscibility was investigated in monolayers composed of binary mixtures of dipalmitoylphosphatidylglycerol (DPPG) and dihexadecyldimethylammonium bromide (DHDAB). Langmuir monolayers formed from biomimetic DPPG/DHDAB mixtures based on the anionic:cationic lipid ratios observed in the bacterium Staphylococcus aureus (7:3 and 1:1) were examined alongside those of the pure amphiphiles and a surfactant rich 3:7 mixture. Using a combination of GIXD, TRXF and IRRAS, DPPG/DHDAB 1:1 monolayers were found to form a more stabilised condensed phase compared to pure DPPG, which was composed entirely of electrostatically neutral ion pairs, analogous to the so-called catanionic amphiphiles spontaneously formed by single-chain surfactants with opposing headgroup charges. Despite the lack of lateral charge repulsion the ion paired phase of DPPG/DHDAB exhibited slightly looser chain packing that was observed for DPPG indicating a significant steric effect on packing geometry caused by ion pair formation. Surprisingly, the 7:3 mixture of DPPG/DHDAB formed a completely condensed phase, with no isotherm transitions, in which the chain packing was significantly closer than was found for either DPPG or the totally ion paired monolayer. It is postulated that this mixture forms a distinct DPPG/DHDAB/DPPG ion triplet phase in which the overall negative charge is delocalised across the headgroups. Vesicles composed from the 7:3 mixture formed highly stable dispersions with an increased gel to liquid crystalline phase transition temperature with respect to its pure components. Increasing the proportion of DHDAB above 50 mol% led to demixing between the condensed ion paired phase and the more fluid surfactant, as was clearly observed in epifluorescence images taken of the surface films., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Copper thiourea complexes are an important material class for application as a precursor of copper sulfide nanocrystals with potential use in solar cells, optoelectronics, medicine, etc. They represent a type of single source precursor, comprising both copper and sulfur in one chemical compound, whose tunable stoichiometry and morphology enable control of the quality and properties of the synthesized copper sulfide nanocrystals. Here, we present a template free electrochemical route to prepare nanowires of copper thiourea (tu) chloride hemihydrate ([Cu(tu)]Cl·½H 2 O) by pulse deposition. We proposed the model of the growth of nanowires. We also demonstrate complete transformation from the precursor to copper sulfide nanowire by heating it to 180 °C that involves 20% volume loss due to the decomposition of organic constituents; the obtained nanowires have around 38% covellite (CuS) and 62% digenite (Cu 1.8 S) phases. Electrochemistry offers the advantage of spatially selected deposition e.g. in the active regions of a device., Competing Interests: There is no conflict of interest to declare., (This journal is © The Royal Society of Chemistry.)

Cardiolipin (CL) plays an important role in administering the structural organization of biological membranes and therefore helps maintaining the integer membrane functionality. CL has a dimeric structure consisting of four acyl chains and two phosphate groups. With its unusual structure, the phospholipid is responsible for curvature formation in CL containing biological membranes. The acidic properties of the phosphate head groups are still not sufficiently investigated since there are controversial results in literature. The main aim of this work was to gain deeper insights into the influence of the pH on the ionization degree of CL. During the experiments, it became clear that the used ultrapure water contained traces of calcium. These unexpected calcium ions had a major impact on the behavior of CL monolayers. Therefore, the focus was put on the analysis of CL layers without and with EDTA in the subphase used to complex divalent calcium ions. For the analyses, traditional surface pressure (π) - molecular area (A) isotherm experiments combined with total reflection x-ray fluorescence (TRXF) and grazing incidence x-ray diffraction (GIXD) have been used., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)