Nanoelectronic systems that are inspired by the brain are increasingly looking to insulator–metal transition (IMT) materials as they can mimic the response characteristics of neurons to temperature changes so that these can be used in robotic and computational applications. V3O5 has an insulator–metal transition at ∼430 or ∼80 K higher than VO2 and provides a unique high-temperature opportunity for these types of applications. In this work, we track the structural evolution of V3O5 thin films across the IMT through conventional selected-area electron diffraction (SAED) and four-dimensional scanning TEM (4D-STEM), correlated with temperature-dependent resistance measurements. SAED patterns show reversible evidence of superlattice reflections associated with the IMT—present below TIMT and absent above it—consistent with the accompanying drop in resistance. At room temperature, nanobeam electron diffraction patterns further reveal three local configurations: (i) type I regions with clean patterns lacking superlattice reflections and spot splitting; (ii) type II regions exhibiting rows of superlattice reflections and split spots indicative of crystallographic variants; and (iii) type III regions with negligible superlattice reflections but larger spot splitting suggestive of overlapping domains of insulating and conducting phases likely driven by local lattice distortions. Upon heating, the superlattice reflections disappear between 413 and 453 K, concurrent with the resistance drop at TIMT, consistent with the emergence of a conducting phase. The overall diffraction geometry remains essentially unchanged up to 573 K, implying that relative domain orientations persist through the transition. These observations reveal nanoscale structural heterogeneity in V3O5 thin films across the IMT and inform operation in regimes where mixed-phase textures are expected. A plausible indexing framework rationalizing the observed geometries is presented in the Discussion section, alongside its limitations and alternative interpretations.

ABSTRACT High-efficiency generation of vortex beams carrying orbital angular momentum (OAM) is pivotal for expanding channel capacity in next-generation terahertz (THz) wireless communications. However, existing THz OAM generators often suffer from trade-offs between operating bandwidth, conversion efficiency, and mode purity. In this paper, we propose and numerically demonstrate an ultra-broadband, high-efficiency reflective metasurface based on the geometric (Pancharatnam-Berry) phase principle. The design utilizes a novel anisotropic “CIC”-shaped meta-atom within a metal-insulator-metal (MIM) architecture, optimized via genetic algorithms to ensure a dispersionless phase response and high birefringence. Full-wave simulations reveal that the metasurface operates across an extensive frequency range of 0.8 to 2.1 THz, achieving a remarkable fractional bandwidth of 86.7%. Within this band, the cross-polarization conversion efficiency exceeds 95%, with stable phase gradients facilitating the generation of high-quality vortex beams with topological charges of l = ± 2 . Furthermore, we perform a comparative analysis between rectangular and circular array topologies, demonstrating that a circular aperture significantly suppresses edge diffraction and enhances OAM mode purity to approximately 0.88. Tolerance analysis further confirms the robustness of the device against typical fabrication errors in dimension and rotation angle. This work provides a compact, high-performance solution for broadband wavefront manipulation, holding significant potential for high-speed THz mode-division multiplexing systems.

Titanium dioxide (TiO2) nanotube arrays (NTAs) were constructed on Ti foil to immobilize Cu2ZnSnS4-TiO2 (CZTS-T/NTAs) via the sol–gel dip-coating technique. The films were characterized by X-ray diffraction (XRD) patterns, field-emission scanning electron microscope–energy dispersive spectroscopy (FESEM-EDX), ultraviolet–visible diffuse reflectance spectra (UV–Vis/DRS), and electrochemical impedance spectroscopy (EIS) techniques. The photocatalytic property of CZTS-T/NTAs was evaluated by the photodegradation of Basic Blue 41 under visible light irradiation. We show that CZTS-T/NTAs have an energy band gap of 2.23 eV, which leads to excellent potential trapping or facilitates the transition of charge carriers under visible light. The parameters R0 and C0 of the experimental EIS data, by fitting the proposed electrical circuit, were also discussed. Decreasing R0 led to an increase in cell capacitance, which resulted in increased carrier generation at the interface between the catalyst and solution and thus an increased photodegradation yield. The response surface methodology (RSM) and central composite rotatable design (CCRD) were used to optimize the effects of the experimental parameters in the degradation process by four key variables (pH, dye concentration, irradiation time, and hydrogen peroxide (H2O2) concentration). As a result, the optimized conditions attained a considerable degradation of 95.25%. We also proposed the possible photodegradation mechanism of the photocatalyst. Notably, the proposed catalyst after six consecutive reuse runs retained activity.

A new Ni II MOF, poly[[sesqui[μ- trans -1,2-bis(pyridin-4-yl)ethylene](μ-thiophene-2,5-dicarboxylato)nickel(II)] dimethylformamide 0.205-solvate], {[Ni(C 6 H 3 O 4 S)(C 12 H 10 N 2 ) 1.5 ].0.205C 3 H 7 NO} n , was obtained under solvothermal conditions and its structure was determined by single-crystal X-ray diffraction. The structure reveals that Ni nodes are bridged by thiophene-2,5-dicarboxylate (HT) and trans -1,2-bis(pyridin-4-yl)ethylene (Bpe) to generate an unusual two-dimensional layered framework, and the overall crystal is formed by an interlocked stacking of these layers. Topological simplification classifies the framework as a non-interpenetrated 3-nodal (2,2,5)-connected net, in which the Ni-containing node acts as the higher-connected vertex and the two organic ligands serve as 2-connected linkers propagating the connectivity within the layer. The experimental powder X-ray diffraction (PXRD) pattern is in good agreement with that simulated from the single-crystal structure, further confirming that the powder sample is consistent with the single-crystal model and exhibits good phase purity.

We investigate the intricate polymorphism of 2D molybdenum ditelluride to unveil the elusive distorted metallic phase, which manifests intriguing non-volatile resistive switching. Employing an evolutionary ab initio structure search, we generate 1600 crystal structures and discover 14 unrecognized low-energy polymorphs, including a distorted metallic phase with P1 group symmetry, designated as DP1. This phase closely resembles the previously observed Hd phase in its diffraction pattern, yet it stands out due to its stability and distinct properties. Our comprehensive variable-cell nudged elastic band calculations reveal that the transition from the semiconducting hexagonal phase to DP1 is non-volatile, with charge doping capable of modulating the SET and RESET barriers. Additionally, phonon dispersion analysis and molecular dynamics simulations confirm DP1’s dynamic and structural resilience. Key findings of our study demonstrate that DP1 serves not as a transient, but as a stable, standalone phase with profound implications for memristor technology.

Abstract We introduce a phase-consistent framework that bridges geometric and wave descriptions of light propagation in inhomogeneous media. By reconstructing the optical phase directly from Hamiltonian optics, we establish a first-principles connection between local refractive-index variations and the emergence of diffraction patterns. The recovered Hamiltonian phase is subsequently propagated using scalar diffraction within Fourier optics, providing a unified description of ray trajectories and interference within a single physical framework. We validate this approach experimentally using thermal-lens diffraction, a paradigmatic system in which continuously distributed refractive-index gradients generate complex interference patterns beyond the scope of thin-lens or ray-optical models. The reconstructed phase quantitatively reproduces the observed diffraction patterns across different transport regimes, demonstrating that diffraction arises directly from accumulated Hamiltonian phase. Beyond thermal lensing, the framework applies broadly to optical and other wave systems governed by an eikonal equation, establishing diffraction as a direct manifestation of Hamiltonian phase accumulation.

Abstract Leather cultural relics are valuable materials for reconstructing and understanding human civilization. However, identifying the tanning agents used in their manufacture remains challenging due to the absence of rapid, non-destructive analytical techniques. This work presents a pioneering non-destructive approach, based on synchrotron small-angle X-ray scattering (SAXS), for identifying vegetable tanned ancient leathers. To validate the method, six simulated ancient leather samples (produced by vegetable, oil, smoke, aluminum, iron, and mirabilite-flour tanning) were analyzed using SAXS, in combination with attenuated total reflectance Fourier transform infrared spectroscopy, X-ray fluorescence, and pyrolysis–gas chromatography-mass spectrometry. SAXS analysis revealed distinctive diffraction patterns: vegetable tanned leathers exhibited minimal or absent peaks due to masking of the collagen fibril D-periodic structure by vegetable tannins, whereas non-vegetable tanned leathers displayed clear periodic diffraction peaks. Application of this method to seven cultural relic samples identified two as vegetable tanned leathers, a result further corroborated by phenolic pyrolysis products detected via pyrolysis–gas chromatography-mass spectrometry. This SAXS-based strategy enables rapid and non-destructive identification of vegetable tanned leather cultural relics. Graphical Abstract

Energy-resolved EBSD using a monolithic direct electron detector.

A combined hardware and software method for the projection center calibration of the diffraction pattern.

Angular resolution enhancement of electron backscatter diffraction patterns.

Analysis of dosimetric characteristics of CaSO4:Mn,Tb phosphors synthesized by four different routes.

Luminescent and optical thermometric behavior of Sm3+ activated LaOBr nanophosphors for display applications and visualization of latent fingerprints.

Autonomous materials science, where active learning is used to navigate large compositional phase space, has emerged as a powerful vehicle to rapidly explore new materials. A crucial aspect of autonomous materials science is exploring new materials using as little data as possible. Gaussian process-based active learning allows effective charting of multi-dimensional parameter space with a limited number of training data and, thus, is a common algorithmic choice for autonomous materials science. An integral part of the autonomous workflow is the application of kernel functions for quantifying similarities among measured data points. A recent theoretical breakthrough has shown that quantum kernel models can achieve similar performance with less training data than classical kernel models. This signals the possible advantage of applying quantum kernel machine learning to autonomous materials discovery. In this work, we compare quantum and classical kernels for their utility in sequential phase space navigation for autonomous materials science. In particular, we compute a quantum kernel and several classical kernels for x-ray diffraction patterns taken from an Fe–Ga–Pd ternary composition spread library. We conduct our study on both IonQ’s Aria trapped ion quantum computer hardware and the corresponding classical noisy simulator. We experimentally verify that a quantum kernel model can outperform some classical kernel models. The results highlight the potential of quantum kernel machine learning methods for accelerating materials discovery and suggest that complex x-ray diffraction data are a candidate for robust quantum kernel model advantage.

A Jungfrau-1M detector has undergone testing at Diamond Light Source. The Jungfrau series of detectors from PSI use integration and adaptive gain, to offer very high frame rate and dynamic range, suitable for high-flux and time-resolved measurements. They are becoming more widely used, to take advantage of increasing light source brightness. We report on our experiences in testing the performance of a Jungfrau-1M without illumination, with a laboratory X-ray tube and on a microfocus beamline. The Jungfrau-1M was found to be able to resolve single photons in the laboratory and on the beamline. It was confirmed that range switching from high to intermediate gain is associated with a discontinuity in the detector response. Two methods of dark frame subtraction were compared for their effect on minimizing this discontinuity. The Jungfrau-1M was found to be very effective for recording macromolecular crystallography diffraction patterns, with no apparent detriment from the discontinuity. The Diamond machine will be upgraded in 2028-9 and will operate at significantly higher flux than at present, necessitating increased use of integrating detectors, such as Jungfrau, in the future.

TRPXv2.0: superfast, parallel compression of diffraction patterns and images, with native Python and HDF5 support.

Software for simulation and analysis of far-field diffraction patterns in transient grating spectroscopy

ABSTRACT Synthetic dyes are major water pollutants because of their persistent toxicity and resistance to biological degradation. Conventional treatment methods are often ineffective, making sustainable alternative approaches necessary. In this study, MgO, NiO, and Co 3 O 4 NPs were synthesized using a green route with Strychnos potatorum seed extract as reducing and stabilizing agent. Structural, functional, morphological, optical, surface area, and thermal properties were characterized by XRD, FTIR, FESEM, UV–vis, BET, and TGA analyses. Photocatalytic performance was evaluated for the degradation of reactive black (RB) and crystal violet (CV) dyes under sunlight. MgO exhibited the highest activity, degrading 99.82% of RB in 75 min and 99.9% of CV in 135 min, followed by NiO and Co 3 O 4 . Recyclability tests showed that all catalysts retained >93% efficiency after seven cycles, confirming recyclability. However, post‐degradation XRD and FESEM revealed morphological changes: cubic‐MgO converted to Mg(OH) 2 with flattened layers, NiO maintained its cubic structure with minor surface changes, and Co 3 O 4 showed phase fluctuations. Post‐calcination restored Mg(OH) 2 to cubic MgO, preserved NiO stability, and reverted the diffraction pattern of Co 3 O 4 with slight suppression. These results demonstrate the efficiency, recyclability, and structural resilience, highlighting their potential as eco‐friendly photocatalysts for sustainable treatment of dye wastewater.

In this work, we present the Fibonacci Tiling-Based Zone Plates (FTZPs) characterized by a Fibonacci binary array generated using complementary substitution rules applied in both horizontal and vertical directions. The resulting array forms a quasiperiodic structured pattern where each row and column corresponds to a Fibonacci sequence or its Boolean complement. This array defines a transmittance function in a normalized spatial domain, partitioned into rectangulars sub-regions. Unlike conventional Fibonacci zone plates, which feature concentric rings, the FTZP consists of transparent and opaque rectangles, offering unique optical properties advantageous for diffraction-based applications. The intensity distribution along the optical axis and the evolution of transverse diffraction patterns are investigated through both numerical simulation and experimental measurements.

Imine-linked two-dimensional covalent organic frameworks (2D COFs) are commonly considered structurally simple materials, yet precise structure determination by X-ray diffraction remains challenging due to the difficulty of obtaining large single crystals. Here, we show that a single-atom change in the aldehyde substituent is sufficient to switch both pore architecture and lattice symmetry in a prototypical 2D COF system. Comparing the widely studied TAPB-DMPDA (COF-OMe) with its -SMe analogue (COF-SMe), we establish a bimodal mesoporous framework for COF-OMe and a unimodal one for COF-SMe through a combination of advanced imaging and diffraction techniques alongside finely sampled gas/vapor physisorption, which resolves two-step capillary processes exclusively in COF-OMe. Electron ptychography reveals previously unrecognized structural features in COF-OMe and enables refinement of its model to propeller-like 1,3,5-tris(4-aminophenyl)benzene nodes with unusually large dihedral angles. Simulated electrostatic potential and X-ray diffraction pattern based on the refined model reproduce the experimental data with high fidelity. COF-SMe undergoes a symmetry reduction from hexagonal to triclinic during kinetic-to-thermodynamic phase evolution, driven by subtle interlayer slippage and intralayer distortion while retaining a single pore type. Together, these results uncover unexpected structural diversity and substituent-governed flexibility in 2D COFs, underscoring the need for state-of-the-art characterization to reassess long-accepted structural models.

Exploring 4D-STEM in SEM with an event-driven direct electron detector: Low-dose, high-speed, and sparse data.