I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[33667]
Open Access
Abstract: Refractory high entropy alloys have gained significant interest over the past decade as promising candidates for high-strength applications, particularly at high temperatures. However, achieving ductility and workability at room temperature remains a challenge for large-scale manufacturing and applications. This study explores the design and characterisation of a novel RHEA with low density, high ductility, and high strength at room temperature. High-throughput screening and experimental validation identified a non-equiatomic composition, Zr35Ti35Nb20V5Al5 (at%), which exhibits a room-temperature yield strength of 1030 MPa, 11% tensile strain to failure, and a low density of 6 g/cm3. The alloy's grain size was refined to <20 μm through rolling and recrystallisation, bypassing traditional high-temperature homogenisation while avoiding microsegregation. The tailored Zr35Ti35Nb20V5Al5 RHEA demonstrates a new design approach and processing route, opening applications in next-generation nuclear and aerospace technologies.
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Aug 2025
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Patrick A.
Robertson
,
James
Merrick
,
David
Heathcote
,
Matthew S.
Robinson
,
Alexander
Butler
,
Yasmine
Biddick
,
J. F. Pedro
Nunes
,
Conor
Rankine
,
Zhihao
Liu
,
Samuel F.
Arrowsmith
,
James O. F.
Thompson
,
M. Nrisimha
Murty
,
Richard
Chapman
,
Emma
Springate
,
Edward A.
Anderson
,
Adam
Kirrander
,
Claire
Vallance
Open Access
Abstract: We report results from a recent laser pump–probe study into the ultrafast ring-opening dynamics of 1,2-dithiane. Following absorption of a 290 nm photon, the nuclear dynamics were probed as a function of pump–probe delay on the femtosecond timescale by strong-field ionisation with an 800 nm probe pulse, resulting in production of a range of atomic and molecular fragment ions. The time-dependent yields of atomic fragment ions reveal evidence of coherent nuclear wavepacket dynamics corresponding to the previously proposed ‘Newton’s cradle’ motion of 1,2-dithiane, in which repeated ring opening, structural inversion, and ring closing occurs on a timescale of
400-500 fs. Based on surface-hopping trajectory simulations of the non-adiabatic dynamics, we are able to rationalise the observed time-dependent ion yields in terms of a geometry-dependent variation in ionisation energy for the photoexcited 1,2-dithiane molecule.
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Jul 2025
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I08-1-Soft X-ray Ptychography
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Abstract: The scales of butterflies display a vast array of vivid colors. However, the exact mechanisms behind these colours are not yet fully understood. Butterfly scales consist of intricate nanostructures that in- teract with light through interference, diffraction, and scattering. Additionally, the nanostructures on butterfly scales vary in pigment density across different species.
A combination of 'pigment effects' and ‘structural effects’ gives rise to the vivid colors observed on a butterfly’s wings. Variations in pigment density have been correlated with specific nanostructures. However, the interplay between pigmentation and nanostructures - how they influence each other - remains largely unexplored. Hence, our work aims to perform a detailed examination of the distribution of various matrix components within butterfly scales, leading to a deeper understanding of not only their colour, but also their role in guiding nano- structure growth.
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Jul 2025
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I05-ARPES
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Zhisheng
Zhao
,
Tongrui
Li
,
Peng
Li
,
Xueliang
Wu
,
Jianghao
Yao
,
Ziyuan
Chen
,
Yajun
Yan
,
Shengtao
Cui
,
Zhe
Sun
,
Yichen
Yang
,
Zhicheng
Jiang
,
Zhengtai
Liu
,
Alex
Louat
,
Timur
Kim
,
Cephise
Cacho
,
Aifeng
Wang
,
Yilin
Wang
,
Dawei
Shen
,
Juan
Jiang
,
Donglai
Feng
Diamond Proposal Number(s):
[32274]
Abstract: The kagome metal FeGe provides a rich platform for understanding the mechanisms behind competing orders, as it exhibits charge order (CO) emerging deep within the antiferromagnetic phase. To investigate the intrinsic origin of this behavior, we examine the evolution of the low-energy electronic structure across the phase transition in annealed FeGe samples using angle-resolved photoemission spectroscopy. We find no evidence supporting a conventional nesting mechanism, such as Fermi surface nesting or van Hove singularities. However, we observe two notable changes in the band structure: an electron-like band around the K point and another around the A point, both shifting upward in energy when CO forms. These findings are consistent with our density-functional theory calculations, which suggest that the charge order in FeGe is primarily driven by magnetic energy savings due to a lattice distortion involving Ge1-dimerization. Our results provide photoemission evidence supporting this novel mechanism for CO formation in FeGe, in contrast to the conventional nesting-driven mechanisms.
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Jun 2025
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Open Access
Abstract: Due to their potential applications in low-power consumption and/or multistate memory devices, multiferroic materials have attracted a lot of attention in the condensed matter community. As part of the effort to identify new multiferroic compounds, perovskite-based GdCrO3 was studied in both bulk and thin film samples. A strong enhancement of the capacitance in a field suggested ferroelectric behaviour but significant leakage and no well developed P–E hysteresis loops were observed. Measurements clearly indicate the existence of a polar phase but only below 2 K (likely connected to Gd ordering). Here the determination of the magnetic structure through neutron diffraction collected on an isotopic 160GdCrO3 sample at the WISH diffractometer at ISIS is reported. The presence of three successive magnetic phases as a function of temperature (commensurate, spin re-orientation and incommensurate phases once the Gd order), previously only seen by magnetization, is confirmed. Using the most recent guidelines for reporting the determined structures, we highlight the benefits of using such nomenclature for discussing physical properties and consider possible mechanisms and couplings that led this seemingly rather isotropic system to display the complex structures observed.
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Jun 2025
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[36775, 26668]
Open Access
Abstract: A variable-temperature and pressure single-crystal diffraction study of hybrid improper ferroelectric Sr3Sn2O7 is reported. In combination with symmetry analysis, we reveal that the application of pressure and temperature induce distinct phase transition pathways, driven by a differing response of the octahedral rotations to these stimuli. Contrary to what has been previously predicted, we observe the ferroelectric to paraelectric phase transition between 10.17(18) and 12.13(14) GPa, meaning the hybrid improper ferroelectric phase remains stable to significantly higher pressures than expected.
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Jun 2025
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Open Access
Abstract: Advancements in macromolecular crystallography, driven by improved sources and cryocooling techniques, have enabled the use of increasingly smaller crystals for structure determination, with microfocus beamlines now widely accessible. Initially developed for challenging samples, these techniques have culminated in advanced beamlines such as VMXm. Here, an in vacuo sample environment improves the signal-to-noise ratio in X-ray diffraction experiments, and thus enables the use of submicrometre crystals. The advancement of techniques such as microcrystal electron diffraction (MicroED) for atomic-level insights into charged states and hydrogen positions, along with room-temperature crystallography to observe physiological states via serial crystallography, has driven a resurgence in the use of microcrystals. Reproducibly preparing small crystals, especially from samples that typically yield larger crystals, requires considerable effort, as no one singular approach guarantees optimal crystals for every technique. This review discusses methods for generating such small crystals, including mechanical crushing and batch crystallization with seeding, and evaluates their compatibility with microcrystal data-collection modalities. Additionally, we examine sample-delivery methods, which are crucial for selecting appropriate crystallization strategies. Establishing reliable protocols for sample preparation and delivery opens new avenues for macromolecular crystallography, particularly in the rapidly progressing field of time-resolved crystallography.
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May 2025
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Lewis J.
Williams
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Amy J.
Thompson
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Philipp
Dijkstal
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Martin
Appleby
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Greta
Assmann
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Florian S. N.
Dworkowski
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Nicole
Hiller
,
Chia-Ying
Huang
,
Tom
Mason
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Samuel
Perrett
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Eduard
Prat
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Didier
Voulot
,
Bill
Pedrini
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John H.
Beale
,
Michael A.
Hough
,
Jonathan A. R.
Worrall
,
Robin L.
Owen
Open Access
Abstract: Serial femtosecond crystallography (SFX) exploits extremely brief X-ray free-electron laser pulses to obtain diffraction data before destruction of the crystal. However, during the pulse X-ray-induced site-specific radiation damage can occur, leading to electronic state and/or structural changes. Here, we present a systematic exploration of the effect of single-pulse duration and energy (and consequently different dose rates) on site-specific radiation damage under typical SFX room-temperature experimental conditions. For the first time in SFX we directly measured the photon pulse duration, varying from less than 10 fs to more than 50 fs, and used three pulse energies to probe in-pulse damage in two radiation-sensitive proteins: the iron-heme peroxidase DtpAa and the disulfide-rich thaumatin. While difference-map features arising from radiation damage are observed, they do not lead to significant change in refined atomic coordinates or key bond lengths. Our work thus provides experimental verification that average atomic coordinates are not significantly perturbed by radiation damage in typical SFX experiments.
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May 2025
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B21-High Throughput SAXS
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Diamond Proposal Number(s):
[31952]
Abstract: Chirality and non-covalent chemistry are essential features in the construction of complex molecular systems that constitute living organisms. The specific interactions between molecular components with defined geometric orientations enable nature’s dynamism, responsiveness, specificity, and selection. The precision with which nature controls its homochirality and functional structures inspired the design of synthetic supramolecular systems. These systems have aimed at understanding the origins of these properties and mimicking their complexity. Research in the last decades has led to many insights into synthetic and natural supramolecular polymerization processes and principles of amplification of asymmetry. However, the complexity observed in nature remains far from being understood. In particular, detailed studies of assembly mechanisms and amplification of asymmetry principles in water-compatible supramolecular systems are scarce due to the challenging contribution of hydrophobic effects leading to non-equilibrium states of supramolecular assemblies. Valuable contributions to this field have been made in recent years, including the introduction of in situ chemical modifications and dissipative non-equilibrium assembly states, leading to evolutionary features such as self-replication. This chapter introduces the concepts of supramolecular polymerization and shows the analogies between natural and synthetic systems. In particular, the influence of homochirality in natural macroscopic structures is emphasized, showing the importance of this property in water-compatible supramolecular systems. Therefore, key developments in research on the origin of homochirality and challenges for future research to understand this essential feature of life are outlined.
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May 2025
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I11-High Resolution Powder Diffraction
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Tianxiang
Chen
,
Yunong
Li
,
Ping-Luen
Ho
,
Kwan Chee
Leung
,
Jinjie
Liu
,
Ching Kit Tommy
Wun
,
Zehao
Li
,
Chiu Chung
Tang
,
Shogo
Kawaguchi
,
Tai-Sing
Wu
,
Yun-Liang
Soo
,
Jun
Yin
,
Shik Chi Edman
Tsang
,
Tsz Woon Benedict
Lo
Open Access
Abstract: A precise understanding of the structure–activity relationship of catalysts is crucial for catalysis research and is essential for rationalizing next-generation catalysts. As the size of catalysts decreases from nanometric to atomic dimensions, the focus on structure–activity relationship correlation has shifted from the “size effect” to the much more challenging “metal nuclearity effect”. However, precise synthesis and reliable characterization for structurally related solid atomic catalysts, such as single-, dual-, and triatom catalysts, still remain extremely challenging. Here, we present the controlled assembly of single-atomic Cu1, dual-atomic Cu2, and triatomic Cu3 supported on zeolites through an innovative atomically choreographed approach. For the first time, we have directly visualized the atomic features of Cu3 with respect to the zeolitic channels using double aberration-corrected scanning transmission electron microscopy (STEM). The structural and electronic properties of the catalysts have been characterized using synchrotron X-ray absorption spectroscopy, high-resolution synchrotron powder X-ray diffraction (PXRD), and density functional theory (DFT) calculations. We revealed the interplay among surface structures, adsorption configurations, catalytic reactivities (showing a significant 25-fold improvement), and product selectivity across structurally related species using a model methanol reforming reaction. We have successfully elucidated the relationship between the metal nuclearity effect and its activity and selectivity in a complex catalytic reaction. Our findings offer an unprecedented opportunity for the catalysis and materials community to finely manipulate the physicochemical properties of this category of solid atomic catalysts to achieve the desired reactivities and selectivities.
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May 2025
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