B18-Core EXAFS
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Weihao
Li
,
Johannes
Döhn
,
Xiao
Han
,
Licheng
Licheng Zhang
,
Dave M.
Pickup
,
Xiong
Xiao
,
Arun
Kumar Samuel
,
Emily R.
Draper
,
Alan V.
Chadwick
,
Stephen
Sproules
,
Stephen
Cottrell
,
Alan J.
Drew
,
Changhua
An
,
Axel
Groß
,
Alexey Y.
Ganin
Diamond Proposal Number(s):
[31218]
Open Access
Abstract: The growing demand for high-performance lithium-ion batteries necessitates the development of cathode materials that combine high capacity, structural stability, and rapid charge–discharge capability. First-principles calculations predict that layered CrSe2 possesses a robust framework capable of accommodating one Li+ per formula unit while intrinsically supporting fast Li-ion diffusion. Muon spin rotation (µ+SR) measurements validate this prediction, revealing fast Li+ diffusion in pre-lithiated CrSe2. Consistent with these findings, electrochemical testing demonstrates a reversible capacity of 125.3 mAh g−1 at 0.1 C, approaching the theoretical value of 127.7 mAh g−1, with stable cycling and good rate capability. In operando X-ray diffraction and electrochemical impedance spectroscopy further reveal a reversible topotactic transition and a lithiation-driven core-shell evolution during cycling. These results show that lithiation-induced conductivity changes govern the electrochemical behavior of CrSe2, highlighting its potential as a high-performance cathode for LIBs. This study provides new insight into intercalation processes in layered transition-metal chalcogenides and informs the design of fast-charging electrodes.
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Feb 2026
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B16-Test Beamline
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Diamond Proposal Number(s):
[31723]
Open Access
Abstract: Out-of-plane fiber wrinkles in carbon-fiber-reinforced polymer laminates trigger premature failure, yet remain difficult to detect and assess. This study introduces a powerful new diagnostic capability: the pairing of X-ray computed tomography (XCT) and Wide Angle X-ray Scattering (WAXS) during in situ compression of specimens containing small (0.2 mm) and large (0.5 mm) wrinkles. This approach enables, for the first time, detailed field-resolved mapping of axial () and radial () lattice microstrain. A new orientation-aware reduction pipeline supports texture classification, peak fitting, and per-point zero-load referencing, requiring minimal intervention and enabling scalable industrial deployment. In large wrinkles, radial microstrain reached −14.5 µ−1, compared to −11.0 µ−1 axially; small wrinkles exhibit approximately one-third of this magnitude. Strain hotspots are identified prior to failure, and tomography confirms these regions as the origin of delamination, matrix cracking, and fiber kink banding. To verify the results analytically, a compact, orientation-aware predictor is developed, reproducing measured fields with a mean absolute error on the order of . These findings establish radial microstrain gradients as a robust, non-destructive indicator of wrinkle severity, providing unique insight and enabling defect behavior to be embedded into full-scale modeling. This supports performance-based rejection criteria and targets inspection in aerospace laminates.
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Dec 2025
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E02-JEM ARM 300CF
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Xinjuan
Li
,
Zhao
Jiang
,
Si
Chen
,
Yi
Tang
,
Bofeng
Xue
,
Tianhao
Wu
,
Yang
Lu
,
Xavier
Moya
,
Akshay
Rao
,
Zhongzheng
Yu
,
Caterina
Ducati
Diamond Proposal Number(s):
[39081]
Open Access
Abstract: Perovskite quantum dots (PeQDs) offer high photoluminescence quantum efficiencies, precise spectral tunability, and solution-processability, making them promising for advanced optoelectronics. However, their structural and defect evolution under thermal stress remains poorly understood. Here, direct nanoscale insights are provided into temperature-driven phase transition and defect dynamics in CsPbBr3 PeQDs using high-resolution, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images, 4D STEM, and photoluminescence spectroscopy. Sub-ångström imaging at room temperature reveals inherent atomic features and octahedral tilting of the lead halide perovskite lattice in PeQDs, suggesting a pre-tilted, low-symmetry state before thermal perturbation. The cryogenic cooling induces a reversible orthorhombic-to-monoclinic phase transition, distinct from bulk perovskite behavior and accompanied by severe strain localization exceeding 20% at surfaces and grain boundaries. A controlled cryogenic post-synthesis treatment can effectively heal defects and improve radiative recombination, whereas prolonged cryo-treatment introduces irreversible structural degradation. These findings highlight the intrinsic structural flexibility of PeQDs and provide a scalable post-synthesis treatment method to optimize the stability and efficiency of QDs for various optoelectronic applications.
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Dec 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[36120]
Open Access
Abstract: Chiral organic glasses combine unique optical properties with the processing advantages of amorphous solids. Here, melt-quenching as a strategy for preparing optically active glasses from enantiopure BINAP (2,2′-bis(diphenylphosphino)-1,1′-binaphthyl), a pivotal ligand in asymmetric catalysis and for luminescent metal complexes is demonstrated. Thermal characterization reveals that only R-BINAP and S-BINAP, not rac-BINAP, form molecular glasses with glass transition temperatures near 100 °C. Pair distribution function analysis and circular dichroism confirm the retention of local structure and homochirality despite the loss of long-range order. Remarkably, the glassy state has a beneficial influence on the molecular optoelectronic properties relative to the crystalline state, resulting in an increase of the radiative rate constant by ≈30%, attributed to more favourable Franck-Condon factors. In addition, a highly unusual simultaneous enhancement of circularly polarized luminescence (CPL) by nearly an order of magnitude is observed, achieving dissymmetry factors |glum| approaching 10−2 that are competitive with the top-performing purely organic molecular chiral emitters reported to date. These findings establish melt-quenched chiral molecular glasses as promising platforms for advanced optoelectronic and photonic materials, combining exceptional chiroptical properties, strong luminescence, and processability without the constraints of crystallinity.
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Nov 2025
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B18-Core EXAFS
I20-EDE-Energy Dispersive EXAFS (EDE)
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Wenyuan
Huang
,
Bing
An
,
Zeyu
Chen
,
Yu
Han
,
Yinlin
Chen
,
Jiangnan
Li
,
Xue
Han
,
Shaojun
Xu
,
Danielle
Crawshaw
,
Evan
Tillotson
,
Sarah J.
Haigh
,
Bing
Han
,
Christopher M. A.
Parlett
,
Luke
Keenan
,
Svemir
Rudic
,
Yongqiang
Cheng
,
Ben F.
Spencer
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[28575, 31729]
Open Access
Abstract: The development of earth-abundant metal-based catalysts is an important goal for the synthesis of fine chemicals. Here, an active nickel catalyst supported on a robust metal–organic framework, MFM-300(Cr), is reported which shows an exceptional performance for reductive amination, a reaction that has long been dominated by noble metals. Ni/MFM-300(Cr) promotes the synthesis of 38 primary amines via reductive amination of their parent carbonyl compounds, including biomass-derived aldehydes and ketones, using NH3 in the presence of H2 operating under relatively mild conditions (5 bar and 160 °C). X-ray absorption spectroscopy confirms the formation of mixtures of metallic Ni0 and Nin+ active sites, while in situ inelastic neutron scattering, coupled with modeling, reveals details of the mechanism of catalysis involving the formation of N-benzyl-1-phenylmethanediamine (BPDI) as an intermediate species in the generation of benzylamine. Cooperativity between Ni sites and MFM-300(Cr) creates an optimal microenvironment for the efficient activation of carbonyl compounds and the selective production of primary amines using a non-precious metal-based catalyst.
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Oct 2025
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I18-Microfocus Spectroscopy
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Jiayi
Guan
,
Bihan
Wang
,
Nana
Li
,
Shang
Peng
,
Ganghua
Zhang
,
Limin
Yan
,
Xuqiang
Liu
,
Kai
Zhang
,
Mingtao
Li
,
Adama
N-Diaye
,
Qingyu
Kong
,
Dongzhou
Zhang
,
Xu
Zhao
,
Ting
Liu
,
Kejun
Bu
,
Yuhong
Mao
,
Gui
Wang
,
Xujie
Lü
,
Xiang
Li
,
Tao
Zeng
,
Wenge
Yang
Diamond Proposal Number(s):
[36140]
Open Access
Abstract: Multiferroic ferroelectric photovoltaic (FPV) materials, combining magnetic and ferroelectric properties, are of paramount importance for optoelectronic and photovoltaic applications. However, optimizing both the remanent polarization and the optical bandgap—key factors for enhanced FPV performance—presents a significant challenge due to their trade-off. This work shows that pressure-induced charge transfer between different metal sites can break this trade-off. Above ≈20 GPa, charge transfer between different trivalent iron (Fe) sites in the multiferroic material BaFe4O7 leads to Fe valence disproportionation, FeO4 tetrahedra disorder, and Jahn–Teller distortion of FeO6 octahedra. These changes reduce the bandgap, lower resistivity, and enhance ferroelectric polarization, resulting in a 2.5-fold increase in photocurrent. Upon decompression, BaFe4O7 retains an order–disorder structure, optimal ferroelectric and optical properties at ambient conditions. This work provides a novel pathway to simultaneously optimizing ferroelectricity and bandgap via pressure-induced charge transfer, overcoming the traditional trade-off in FPV materials, and offers a promising approach for developing high polarization performance, narrow-bandgap FPV materials.
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Aug 2025
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Haozhe
Zhang
,
Mengqi
Duan
,
Shuai
Guo
,
Renzo
Leeflang
,
Dorottya
Szalay
,
Jiasi
Li
,
Jo-Chi
Tseng
,
Simson
Wu
,
Songhua
Cai
,
Dharmalingam
Prabhakaran
,
Robert A.
Taylor
,
Yiyang
Li
,
Shik Chi Edman
Tsang
Open Access
Abstract: Photocatalytic ammonia decomposition offers a sustainable route for hydrogen production, but its development is limited by low catalytic efficiency and poorly understood mechanisms. Here, a protonated layered perovskite, HPrNb2O7 (HPNO), is reported as an efficient catalyst for ammonia decomposition under mild photo-thermal conditions. Upon exposure to NH3 at elevated temperatures, HPNO promotes the in situ formation and intercalation of hydrazine intermediates within its interlayer galleries, enabled by thermally generated oxygen vacancies and hydrogen bonding. Advanced characterization techniques have been applied to confirm the formation and stabilization of hydrazine. It is also shown that thermal energy prolongs charge carrier lifetimes and enhances oxygen vacancy formation, contributing to a strong photo-thermal synergy. The stabilization of hydrazine intermediate promotes the associative mechanism, lowering the activation barrier, thus leading to an enhanced hydrogen evolution rate of 1311.2 µmol·g−1·h−1 at 200 °C under simulated solar irradiation without any noble metal co-catalyst. This work reveals a distinct, hydrazine-mediated reaction pathway and positions layered protonated perovskites as promising materials for efficient, solar-driven ammonia decomposition and sustainable hydrogen generation.
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Aug 2025
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E01-JEM ARM 200CF
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Emerson C.
Kohlrausch
,
Sadegh
Ghaderzadeh
,
Gazi N.
Aliev
,
Ilya
Popov
,
Fatmah
Saad
,
Eman
Alharbi
,
Quentin M.
Ramasse
,
Graham A.
Rance
,
Mohsen
Danaie
,
Madasamy
Thangamuthu
,
Mathew
Young
,
Richard
Plummer
,
David J.
Morgan
,
Wolfgang
Theis
,
Elena
Besley
,
Andrei N.
Khlobystov
,
Jesum
Alves Fernandes
Diamond Proposal Number(s):
[37379, 38763]
Open Access
Abstract: 2D metal clusters maximize atom–surface interactions, making them highly attractive for energy and electronic technologies. However, their fabrication remains extremely challenging because they are thermodynamically unstable. Current methods are limited to element-specific binding sites or confinement of metals between layers, with no universal strategy achieved to date. Here, a general approach is presented that uses vacancy defects as universal binding sites to fabricate single-layer metal clusters (SLMC). It is demonstrated that the density of these vacancies governs metal atom diffusion and bonding to the surface, overriding the metal's physicochemical properties. Crucially, the reactivity of vacancy sites must be preserved prior to metal deposition to enable SLMC formation. This strategy is demonstrated across 21 elements and their mixtures, yielding SLMC with areal densities up to 4.3 atoms∙nm⁻2, without heteroatom doping, while maintaining high thermal, environmental, and electrochemical stability. These findings provide a universal strategy for stabilizing SLMC, eliminating the need for element-specific synthesis and metal confinement protocols and offering a strategy for efficiently utilizing metals.
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Jul 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[30534]
Open Access
Abstract: A comprehensive understanding of the solid electrolyte interphase (SEI) is crucial for ensuring long-term battery stability. This is particularly pertinent in sodium-ion batteries (NIBs), where the SEI remains poorly understood, and investigations are typically undertaken in half-cell configurations with sodium metal as the counter electrode. Na metal is known to be highly reactive with common carbonate-based electrolytes; nevertheless, its effects on SEI formation at the working electrode are largely unexplored. This work investigates the evolution of the SEI in NIBs during cycling, with an emphasis on the consequences of using a sodium metal counter electrode. Advanced analytical techniques, including hard X-ray photoelectron spectroscopy (HAXPES) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), are used to obtain depth-resolved insights into the chemical composition and structural changes of the SEI on hard carbon anodes during cycling. The findings demonstrate that the cell configuration has a significant impact on SEI evolution and, by extension, battery performance. These findings suggest that full-cell studies are necessary to better simulate practical operating conditions, challenging traditional half-cell experiments.
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Jun 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[31918]
Open Access
Abstract: The discovery of ferroelectric phases in HfO2-based films has reignited interest in ferroelectrics and their application in resistive switching (RS) devices. This study investigates the pivotal role of electrodes in facilitating the Schottky-to-Ohmic transition (SOT) observed in devices consisting of ultrathin epitaxial ferroelectric Hf0.93Y0.07O2 (YHO) films deposited on La0.67Sr0.33MnO3-buffered Nb-doped SrTiO3 (NbSTO|LSMO) with Ti|Au top electrodes. These findings indicate combined filamentary RS and ferroelectric switching occurs in devices with designed electrodes, having an ON/OFF ratio of over 100 during about 105 cycles. Transport measurements of modified device stacks show no change in SOT when the ferroelectric YHO layer is replaced with an equivalent hafnia-based layer, Hf0.5Zr0.5O2 (HZO). However, incomplete SOT is observed for variations in the top electrode thickness or material, as well as LSMO electrode thickness. This underscores the importance of employing oxygen-reactive electrodes and a bottom electrode with reduced conductivity to stabilize SOT. These findings provide valuable insights for enhancing the performance of ferroelectric RS devices through integration with filamentary RS mechanism.
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Jan 2025
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