Production and manipulation of orbital angular momentum (OAM) of coherent soft X-ray beams is demonstrated utilizing consecutive diffractive optics. OAM addition is observed upon passing the beam through consecutive fork gratings. The OAM of the beam was found to be decoupled from its spin angular momentum (SAM). Practical implementation of angular momentum control by consecutive devices in the X-ray regime opens new experimental opportunities, such as direct measurement of the beam's OAM without resorting to phase-sensitive techniques, including holography. OAM analyzers utilizing fork gratings can be used to characterize the beams produced by synchrotron and free electron lasers sources; they can also be used in scattering experiments.

Low‐pressure carburizing (LPC) is a thermochemical process that enriches steel surfaces with carbon. While LPC is already used in industry, there are still aspects that offer opportunities for optimization if the necessary basic process understanding is provided. The present study quantifies the effect of LPC process parameters on the material state of different steel grades. For this purpose, in situ carburizing and quenching experiments are performed in a custom‐built chamber for synchrotron X‐ray diffraction at the German Electron Synchrotron in Hamburg. During carbon enrichment, carbon saturation and carbide formation are observed, slowing acetylene decomposition. Carbides that initially form at the surface dissolve in later diffusion steps. The kinetics of carbide formation and dissolution strongly depend on steel grade and carbide size. Quenching experiments further enable systematic analysis of phase‐specific stresses at the surface and subsurface. The influence of transformation temperature across the carbon gradient is tracked, revealing differences in maximum stresses in both austenite and martensite. A direct correlation is identified between the local martensite fraction and the generated stresses within the carburized layer. This work provides new experimental insights into carbon uptake, carbide evolution, and stress development during LPC, offering pathways for process optimization across different steel types.

Ferroelastic phase transitions lead to the formation of ferroelastic twins, resulting in spatial inhomogeneities in the crystal structures and functional properties of ferroelastic materials. Despite the importance of such nanoscale twins in oxide heterostructures, their direct, non-invasive observation has relied on cumbersome and low-throughput techniques such as transmission electron microscopy and synchrotron X-ray diffraction, or been restricted to materials with coexistence of ferroelectric and ferroelastic states, by detecting the coupled ferroelectric order. In this study, the application of electron channeling contrast imaging (ECCI) in a scanning electron microscope for imaging ferroelastic domains in various oxide heterostructures is demonstrated. These include systems where ferroelasticity is coupled with critical functional properties such as ferroelectricity, magnetism and charge transport. The versatility of this imaging method is highlighted across different heterostructure geometries, from bare thin films to multilayers, achieving an impressive resolution of 6nm. ECCI presents a powerful approach for exploring the rich spectrum of ferroelasticity-coupled phenomena in oxide heterostructures.

Multilayer mirrors for the water window spectral range (photon energies from 284 to 543 eV, which correspond, respectively, to the C–K and O–K absorption edges) have become key components for microscopy, synchrotron and free electron laser sources, semiconductor microanalysis, and x-ray spectroscopy. The emergence of new x-ray sources and new applications in this spectral domain (e.g., soft x-ray photolithography and attosecond science) requires more efficient optical components with precise metrology of their performance. We have recently reported high experimental peak reflectance at near-normal incidence near the Sc L2,3 absorption edge (E ≈ 400 eV) by the experimental optimization of Cr/Sc-based multilayers. The short wavelength and the large number of multilayer periods raise some specific issues for the at-wavelength reflectance measurements. We report here on a systematic study of potential bias in the measurements of high-reflectance multilayer mirror in the water window based on a comparison between experimental data from the three different synchrotron beamlines as well as theoretical calculations and simulations. In particular, we discuss the effects of spectral resolution and angular resolution on the peak reflectance as well as the influence of the sample lateral uniformity and of the light scattered by the multilayer sample (diffuse scattering). As a result of this study, we determined the peak reflectance of this multilayer mirror to be 35% at E = 396 eV at near-normal incidence, which is the highest reflectance reported in the water window spectral range.

Abstract The article presents the automation of radiation surveys in the Super Proton Synchrotron (SPS) accelerator using autonomous robotic navigation techniques. The mission plan includes precise radiation monitoring along beam components; navigation along walls; crossing safety doors; maneuvering in open spaces (e.g., entrances and the beam dump area); deploying a manipulator-mounted radiation sensor; and docking or undocking at charging stations for long-term operations. Two mobile manipulators are deployed underground and operated via a multimodal telerobotic graphical user interface (GUI), which enables mission launches in Autopilot mode, supervision of operations, parameter adjustments (e.g., velocity, distances, positions), and manual intervention when required. The core contribution is the development of navigation techniques that enable fully autonomous radiation surveys, thereby enhancing safety, reducing operator workload, and standardizing measurements. Key features include an Autopilot system for the SPS arc tunnel that leverages LiDAR mapping, clustering, and visual segmentation. The article also presents solutions for automated gate crossing and parking. In complex areas—such as the beam dump area and the six access points—the SLAM Karto algorithm enables goal-directed navigation. Mapping results and techniques are discussed. Finally, the article highlights additional applications, including the use of the Autopilot during the Measurement and Inspection Robot for Accelerators (MIRA) test campaign at the DESY institute.

This article examines the influence of unintentional Cr3+ and Fe3+ impurity ions on the luminescent properties of Gd3Ga5O12 (GGG) single crystals. The characteristic features of the spectra excited by high-energy syn chrotron radiation in the temperature range of 10–300 K are analyzed. It is shown that at 10 K the lumines cence is dominated by a narrow-band emission of Cr3+ ions arising from the spin-forbidden 2E→4A2 transi tion, which indicates weak electron–phonon coupling and high crystalline homogeneity. It is revealed that with increasing temperature the intensity of this transition decreases significantly, while a broadband lumi nescence emerges, associated with the spin-allowed 4T2→4A2 transition and the contribution of Fe3+ ion emis sion. The temperature evolution of the spectra is shown to result from thermal redistribution of the Cr3+ excit ed-state populations, interlevel state mixing, and partial removal of the spin-forbidden nature of Fe3+ transi tions due to lattice vibrations. Based on the study, conclusions are drawn regarding the role of impurity cen ters in energy transfer and nonradiative relaxation processes. The results are of interest both for fundamental photonics and for the development of efficient luminescent materials and optical devices designed to operate over a wide temperature range.

In situ observation of soft X-ray-triggered nanoscale phase transitions in perfluorocarbon microdroplets.

Oligonucleotide-functionalized nanoparticles (NPs), known as "programmable atom equivalents" (PAEs), are the primary building blocks for the field of colloidal crystal engineering with DNA. With these constructs, one typically uses canonical DNA-DNA interactions to control the colloidal crystallization process. Herein, DNA-modified perylene diimides that can assemble into spherical micellar PAEs are synthesized and characterized. These PAEs are held together via noncovalent interactions, and therefore both chemical and physical stimuli can be used to disassemble them and, consequently, modulate the structures of colloidal crystals made from them. When combined with gold nanoparticle PAEs of approximately the same size but with complementary DNA, these micellar PAEs assemble into BCC colloidal crystal lattices. Electron microscopy, UV-vis spectroscopy, and synchrotron small-angle X-ray scattering studies confirm the structural assignment. Spectroscopic and microscopy studies show that anionic aromatic molecules (1,3,6,8-pyrenetetrasulfonate) are capable of disrupting the supramolecular PAEs, which leads to disassembly of the colloidal crystal lattice. Molecular dynamics simulations and first-principles calculations provide further insight into the PAE core assembly process and notably suggest that it is independent of DNA valency and sequence. This work is important because it introduces a new strategy and extralattice chemical parameter for controlling colloidal crystals engineered with DNA.

α‐Sn has recently been attracting significant interest due to its unique electronic properties. However, alternative strategies to the conventional epitaxial growth on InSb to stabilize it at room temperature and the ability to manipulate its bandgap are still a challenge. In this work, a complementary metal oxide semiconductor (CMOS)‐compatible process employing microwave irradiation is used to synthetize α‐Sn nanoparticles (NPs) of different size on a Si substrate. Morphological characterizations suggest the possibility to control the average Sn NPs size by means of a combined dewetting and coalescence process induced by the microwaves on Sn films. Transmission Electron Microscopy (TEM) and Synchrotron Radiation‐Grazing Incidence X‐ray Diffraction (SR‐GIXRD) analyses confirm the stabilization of the α‐Sn phase within an oxide shell, while X‐ray Photoelectron Spectroscopy (XPS) measurements allow tracking the oxide shell evolution and reveal the opening of a bandgap. Optical investigation demonstrates unprecedented tunability of the ultranarrow bandgap energy of α‐Sn between 64 and 137 meV (15–35 THz). The observed bandgap modulation with NPs size is consistent with a quantum confinement effect, which suggests the proposed approach as an effective strategy for tuning the α‐Sn bandgap and broadening its potential for a CMOS‐compatible integration in next‐generation terahertz technologies.

Strain engineering, enabling the precise control over structure and functional properties, is a key strategy for the design of advanced materials. However, the mechanisms governing strain evolution and release at the nanoscale remain largely unexplored. In this study, we leverage in situ heating transmission electron microscopy and synchrotron x-ray spectroscopy to investigate the strain relaxation pathways of boehmite (γ-AlOOH) at 575 kelvin by revealing real-time structural dynamics. Through tracking the moiré pattern evolution, we identify distinct strain release mechanisms, including layer twisting, defect formation, and domain restructuring. Our neural network potential calculations reveal that energy fluctuations at small twist angles are dominated by an interference-like interaction modulation of hydrogen bonds between boehmite interlayers, with metastable twisted structures corresponding to local minima of the potential energy landscape. This work establishes a previously unidentified paradigm of two-dimensional layer twisting mediated by hydrogen bonding, offering insights into strain-driven transformation mechanisms, and thus may have broad implications for strain in material and earth sciences.

Abstract Al–Mg alloys are becoming major industrial materials that are particularly suitable for applications requiring protection against electromagnetic radiation. This study investigates morphology and kinetic of the intermetallic phases growth in multilayer system produced via single-shot explosive welding, focusing on eleven-layer composite comprising sheets of AZ31 magnesium and AA1050 aluminium alloys. The microstructure and chemical-composition at the bonding interfaces of the composites were characterised in both the as-welded and post-heat-treated states using scanning and transmission electron microscopy and synchrotron X-ray diffraction. The mechanical properties of the interfacial layers were evaluated using microhardness measurements and shear testing. All interfaces exhibited localised melting followed by rapid solidification during explosive welding. This resulted in the formation of non-equilibrium phases comprising amorphous and/or ultrafine-grained structures, alongside two equilibrium phases: γ -Mg 17 Al 12 and β- Mg 28 Al 45 . Short-duration annealing (< 1 hour) at 673 K promoted significant growth of the γ and β phases near all interfaces and induced the transformation of the pre-existing non-equilibrium phases within the reaction regions into the β phase. Prolonged annealing (≥ 500 hours) induced the formation of layers of an intermediate ε- Mg 22 Al 20 phase between layers of the β and γ phases. Complete interdiffusion between the AA1050 and AZ31 layers, leading to the formation of a γ/ε/β -phase multilayered structure, required annealing times exceeding 10 3 hours. Although all three intermetallic phases were significantly harder than the base alloys, structural discontinuities within the β phase markedly reduced interfacial strength. To mitigate this effect, annealing should be carried out under moderate compressive stress in a closed-die configuration, with tightly controlled heating and cooling rates. Graphical Abstract

The National Laboratories in Frascati (LNF INFN) were conceived and created by a group of collaborators of Enrico Fermi, including Edoardo Amaldi, Gilberto Bernardini, and Enrico Persico, after World War II, with the goal of hosting a 1 GeV electron synchrotron for nuclear physics [...]

Sulfur radicals are highly reactive intermediates that can greatly accelerate reaction kinetics in lithium-sulfur batteries. However, the intrinsic instability restricts their applications. Herein, we reveal and validate the formation of ultrastable triplet sulfur radical pairs ([Sx·- - Sx·-], x = 2, 3, 4) by combining electron paramagnetic resonance and synchrotron radiations. These radical pairs are produced during the spontaneous decomposition of polysulfide molecules on ferrimagnetic surface, where the sulfur radicals adopt parallel spin alignment and pair into stable triplet states through Hund's Rule. These radicals enable exceptionally rapid sulfur conversion, delivering a 100-fold kinetic enhancement compared to the traditional polysulfide molecules. Using these triplet radical pairs, the lithium-sulfur battery achieves a remarkable discharge capacity of 728 mAh g-1, even at an ultrahigh current rate of 8.0 C, with high sulfur loading and lean electrolyte. Significantly, this is the highest capacity under ultrafast charge-discharge rates reported to date.

Abstract Enthesis lesions are one of the prevalent causes of injuries in the tendon tissue. The gradient of mineralization, extracellular matrix organization and auxetic mechanical properties, make enthesis regeneration challenging. Innovative electrospun fascicle‐inspired nanofibrous poly(L‐lactic)acid/collagen type I blend scaffolds are developed. Specifically, a mineralized fibrocartilage‐inspired region (with/without nano‐mineralization with hydroxyapatite), where random and aligned nanofibers coexist, is connected to a tendon‐like region made of aligned nanofibers, through a conical non‐mineralized fibrocartilage‐inspired junction. Scanning electron microscopy and synchrotron X‐ray nano‐tomography show the morphological biomimicry of scaffolds with the natural tendon fascicles. Cultures of human mesenchymal stromal cell spheroids confirm a balanced expression of both tendon, cartilage, and bone markers on the non‐mineralized scaffolds compared with the mineralized ones. Mechanical tests, at different physiological strain‐rates, reveal a biomimetic mechanical behavior of scaffolds and the ability of junctions to tune the mechanics of their surrounding sites. Multiscale synchrotron in situ tensile tests, coupled with digital volume correlation, elucidate the full‐field strain distribution of scaffolds from the structural down to the nanofiber level, highlighting the auxetic mechanical behavior of junctions typical of the natural enthesis. The findings and cutting‐edge investigations of this study suggest the suitability of these enthesis‐inspired fascicles as innovative scaffolds for enhanced enthesis regeneration.

In recent years, time-resolved serial crystallography has emerged as a transformative technique for unraveling the intricate dynamics of macromolecules at atomic resolution. By leveraging the high-intensity and ultra-short pulses of X-ray free electron lasers (XFELs) alongside the high brilliance of synchrotron light sources, this technique has enabled the observation of transient states in biomolecules as they catalyze chemical reactions.This presentation will highlight the advancements and applications of time-resolved serial crystallography in the study of macromolecular dynamic. We will discuss the light-sensitive membrane protein Nonlabens marinus halorhodopsin (NmHR) as an example of how this method enables us to capture the structural dynamics from femtoseconds to milliseconds after light activation. Through combining time-resolved studies at the X-ray free electron laser and synchrotron with spectroscopy and chemical simulation, we obtained a comprehensive understanding of the molecular mechanism that allows NmHR to catalyze ion transport across biological membranes. In addition to discussing the rich chemical information that can be obtained in time-resolved crystallographic studies, this talk will highlight how steady-state experiments can provide exciting structural insights while requiring only a limited amount of beamtime and a minimal setup.

Diffuse nonthermal (NT) emission from the central starburst (CSB) region of M82 has been measured at radio, X-ray, and γ-ray energies. Far-infrared (FIR), radio, and X-ray emission maps are mutually consistent, with the radio and X-ray emissions being spectrally similar. These observational results suggest that NT X-ray emission is likely produced in Compton scattering of radio emitting electrons off the ambient FIR field. We present results of our analysis of 16.3 years of Fermi -LAT measurements, which -- combined with the newly published, improved VERITAS point-source data -- constitute the deepest, most extensive currently available γ-ray dataset on M82. We aim to self-consistently model the NT radio to γ-ray spectral energy distribution (SED) of the CSB as emission by relativistic electrons and protons. Key features of our models are the use -- for the first time in a broadband NT spectral study of a starburst galaxy -- of diffuse X-ray and radio emission from the CSB region, which allow for an overall calibration of the electron spectrum, and the identification of the magcir50 GeV emission as pionic in origin. This enables the determination of the zero-point and slope of the proton (and secondary electron) spectrum, and meaningful estimates of the energy densities of particles and magnetic fields. We consider all relevant radiative and adiabatic processes involving relativistic and thermal electrons and protons. We use detailed descriptions of the radiation fields in the CSB region, the most important of which is the local FIR field, a graybody parametrized by the dust emission index and temperature (β, T_̊m d). Our SED modeling indicates that (i) the magcir10 GeV emission is mostly pionic (ii) the $0.1 ̊m GeV emission is a combination of pionic and Compton-scattered interstellar light (and subdominant NT bremsstrahlung) (iii) the mincir0.1 GeV γ-ray emission is leptonic, and (iv) the radio spectrum arises from primary and secondary electron synchrotron emissions at comparable levels. The primary and secondary electron populations are described by a power-law spectrum and a curved spectrum, respectively. Averaged over the set of viable FIR graybody models, the proton spectral index and energy density are q_p ≃ 2.3 and u_p ≃ 385 eV cm^-3 (for $n_ ̊m H = 200$ cm^-3), the (primary) electron and proton maximum energies are ∼30 GeV and 7 TeV, respectively, and the magnetic field is $B ≃ 120,μ$G. The derived particle and magnetic energy densities are in approximate equipartition.

Abstract Ti-6Al-4V (Ti-64) is one of the most widely used α + β titanium alloys. During its thermomechanical processing, strong and heterogeneous crystallographic textures can develop that are detrimental to mechanical performance. Existing texture data for Ti-64 in the α + β regime is limited and lacks detail on how the texture of both the hexagonal close-packed (HCP) α and body-centred cubic (BCC) β phases evolve during hot deformation. In this study, a comprehensive dataset of α and β textures was generated from hot rolling experiments at nine temperatures (825–1020 °C) and three rolling reductions (up to 87.5 pct), with different starting microstructures. High-throughput electron backscatter diffraction and synchrotron X-ray diffraction were used to characterise texture development. Results show that a moderate 0002//TD α alignment forms at all subtransus temperatures and becomes dominant above 895 °C, increasing with both strain and temperature. In contrast, the β texture remains weak at lower temperatures but develops a strong $$\left\{001\right\}\langle 110\rangle $$ 001 ⟨ 110 ⟩ rotated cube component near and above the β-transus. Lamellar-starting microstructures led to slightly stronger textures but similar texture components. The full dataset has been made publicly available to support future modelling efforts and improve understanding of dual-phase texture development in titanium alloys.

Abstract In order to enhance the ferroelectric properties, composite nanoparticles with a core–shell structure were prepared, and since BaTiO3 (BT) core and KNbO3 (KN) shell form a hierarchical structure, structural analysis was performed at various scales using a combination of synchrotron radiation and electron microscopy. The KN shell layer was epitaxially grown on the BT core and exhibited a distinct structure from the bulk. Additionally, the local structure and chemical bonding state of the KN shell layer exhibited discrepancies from those of the bulk, a phenomenon attributable to the two-dimensional growth and epitaxial effects analogous to those observed in thin films. There were significant changes in the electronic states not only at the interface with the core, but also at the surface of the shell layer. Composite nanoparticles can effectively modify the chemical bonding states of ferroelectrics through the effects of dimensionality and size.

Abstract We model the transport and spectral evolution of 1–100 GeV cosmic-ray electrons (CREs) in TIGRESS magnetohydrodynamic simulations of the magnetized, multiphase interstellar medium. We postprocess a kpc-sized galactic disk patch representative of the solar neighborhood using a two-moment method for cosmic ray (CR) transport that includes advection, streaming, and diffusion. The diffusion coefficient is set by balancing wave growth via the CR streaming instability against wave damping (nonlinear Landau and ion–neutral collisions), depending on local gas and CR properties. Implemented energy loss mechanisms include synchrotron, inverse Compton, ionization, and bremsstrahlung. We evaluate CRE losses by different mechanisms as a function of energy and distance from the midplane, and compare loss timescales to transport and diffusion timescales. This comparison shows that CRE spectral steepening above p = 1 GeV c−1 is due to a combination of energy-dependent transport and losses. Our evolved CRE spectra are consistent with direct observations in the solar neighborhood, with a spectral index that steepens from an injected value of −2.3 to an energy-dependent value between −2.7 and −3.3. We also show that the steepening is independent of the injection spectrum. Finally, we present potential applications of our models, including to the production of synthetic synchrotron emission. Our simulations demonstrate that the CRE spectral slope can be accurately recovered from pairs of radio observations in the range 1.5–45 GHz.

PROTACs are new drug molecules in the beyond Rule of Five (bRo5) chemical space with extremely poor aqueous solubility and intrinsically poor crystallizability due to their structure, which comprises two distinct ligands covalently linked by a flexible linker. This makes PROTACs particularly challenging to understand from a solid-state preformulation perspective. While several X-ray structures have been reported of PROTACs in ternary complexes, to date no structures have been published of single component densely packed PROTACs, from which an understanding of PROTACs' intermolecular interactions, and therefore physical properties, can be developed. An extensive crystallization protocol was applied to grow single crystals of a cereblon-recruiting PROTAC "AZ1" resulting in structures of an anhydrous form and a nonstoichiometric p-xylene solvate using 3D electron diffraction and synchrotron X-ray crystallography, respectively. The lattice energies are dominated by dispersive interactions between AZ1 molecules despite the presence of multiple hydrogen-bond donors and acceptors and planar aromatic groups, and both structures are built on similar intermolecular interactions. Thermal and spectral characterization revealed another solvate form containing dichloromethane. Amorphous solids produced by mechanochemical grinding of anhydrous AZ1 crystals also differed in dissolution characteristics from an amorphous solid produced by desolvating the dichloromethane solvate crystals, indicating that AZ1 may demonstrate pseudo-polyamorphism. This study paves the way for solid form screening and understanding in pharmaceutical systems that are far bRo5.