I09-Surface and Interface Structural Analysis
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Uday
Kushwah
,
Shiyang
Lu
,
Prajna
Bhatt
,
Aysha A.
Riaz
,
Pardeep K.
Thakur
,
Tien-Lin
Lee
,
Marco
Kirm
,
Vitali
Nagirnyi
,
Tanel
Käämbre
,
Johannes
Lischner
,
Anna
Regoutz
,
Juhan Matthias
Kahk
Diamond Proposal Number(s):
[36189]
Open Access
Abstract: Ultrafast scintillators based on ternary hexafluorides are promising for next-generation radiation detectors, which can be used in time-of-flight positron emission tomography. To gain a detailed understanding of the scintillation mechanism in these materials, accurate knowledge of the electronic band structure is required. In this study, photoelectron spectroscopy, density-functional theory, and G0W0 calculations were used to investigate the electronic structure of K2SiF6. The G0W0 calculations predict a wide band gap of 12.4 eV reflecting the strongly ionic character of the bonding. In contrast to predictions from semi-local or hybrid density-functional theory calculations, the large band gap predicted by G0W0 suggests that Auger-Meitner decay of K 3p holes is energetically not allowed and that scintillation via cross-luminescence is possible in this material. However, the poor light-yield observed experimentally indicates that the exclusion of Auger-Meitner decay is not sufficient for good scintillation performance, and cross-luminescence competes with other decay channels.
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Jul 2026
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I15-1-X-ray Pair Distribution Function (XPDF)
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Laura G.
Graversen
,
Nicolas
Schlegel
,
Freja B.
Holde
,
Adrian
Sanz Arjona
,
Stefanie
Punke
,
Tobias M.
Nielsen
,
Andy S.
Anker
,
Jonas
Forner
,
Gustav K. H.
Wiberg
,
Matthias
Arenz
,
Rebecca K.
Pittkowski
,
Kirsten M. Ø.
Jensen
Diamond Proposal Number(s):
[30653]
Open Access
Abstract: Iridium oxide nanoparticles are efficient catalysts for the acidic oxygen evolution reaction (OER). We present a straightforward one-pot hydrothermal synthesis method to produce sub-1 nm Ir oxide nanoparticles in a single step, with size control achieved through post-synthesis annealing. By combining X-ray total scattering and pair distribution function (PDF) analysis with small-angle X-ray scattering (SAXS), we find that the sub-nanometer-sized oxide has an increased number of edge-sharing [IrO6]-octahedra compared to the thermodynamically favorable rutile structure. PDF modelling using various cluster motifs reveals that a sheet-like cluster, derived from rutile and comprising seven [IrO6]-octahedra with a (110)-exposed surface, can describe the increased Ir–Ir edge-sharing connectivity. We further find that cluster growth leads to a decrease in the number of edge-sharing motifs, going towards the bulk rutile structure upon annealing. Operando X-ray total scattering and PDF analysis during OER reveal high structural stability of the ultra-small (<3 nm) Ir oxides.
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Jun 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[37966]
Open Access
Abstract: With the ongoing interest in developing more stable and versatile catalysts for CO2 hydrogenation to methanol, molybdenum sulfide (MoS2) has been recently proposed as an alternative material. However, in its bulk state, CO2 hydrogenation over MoS2 typically favors methane formation. In this work, a wet impregnation method is applied for the production of ZnS-supported MoS2, as confirmed by characterization via X-ray Diffraction, Raman and X-ray Photoelectron Spectroscopy. In contrast with the negligible methanol production shown by the pure MoS2 reference, 2% MoS2/ZnS presents a methanol selectivity of 78% at a CO2 conversion of 2.3% under the mild reaction conditions of 200 °C and 20 bar. Density Functional Theory and Transmission Electron Microscopy suggest that the improved catalytic activity arises from an even dispersion of few-layer MoS2 with exposed basal plane sites at the ZnS surface, an arrangement possibly enabled by the structural similarity and the shared S atoms between 2H-MoS2 and W–ZnS phases. This hypothesis is strengthened by the comparison with the reference sample consisting of ZrO2-supported MoS2 sample, in which more agglomerated MoS2 particles resulted in a lower and less selective methanol production. Moreover, in situ X-ray absorption spectroscopy and H2 temperature-programmed reduction suggest further evidence of a MoS2/ZnS interaction during the H2 pretreatment, which may promote not only the expected formation of S-vacancies but also a partial reconstruction of MoS2 given the close contact and sharing of S atoms with the ZnS support.
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Jun 2026
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[34243]
Open Access
Abstract: A key challenge for incorporation of oxide-based solid electrolytes into batteries remains the brittle nature of the ceramic, which makes scalable, low-cost fabrication of thin (<20 µm) separators challenging. solution-based processing, involving the direct liquid-to-solid transformation of a precursor solution into a ceramic film through deposition and annealing, offers an attractive route to overcome these fabrication challenges while significantly reducing processing temperatures compared to conventional solid-state methods. However, the relationship between the initial choices made in precursor chemistries and the crystallization behavior remains poorly understood, limiting control over the phase formation process. Here, we investigate how the precursor decompositions influence the structure evolution during annealing and crystallization of solution-processed Li-garnet solid electrolyte films. The results reveal a sequence of solvent and precursor decompositions with the Li-precursor, LiNO3, decomposition occurring last and in parallel with the nucleation of La2Zr2O7 as the first crystalline metal-oxide phase. Upon Li-precursor decomposition, the latter is lithiated to form the desired highly conductive cubic Li6.25Al0.25La3Zr2O12 phase. This simultaneity of crystallization and decomposition events demonstrates the importance of the initial precursor choices to control the crystallization process. Through this work, we contribute to fundamental ceramic materials science by establishing a systematic methodology for studying solution-processing and providing a foundation for future precursor design of next-generation solid electrolyte battery components.
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May 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[14239]
Open Access
Abstract: Ni-rich layered oxides such as (LiNixMnyCo1−x−yO2 (x ≥ 0.6)) exhibit structural degradation, surface instability, and poor lithium ion transport, particularly under extreme temperature conditions, limiting their viability for next generation high energy batteries. This work demonstrates that low-level boron (B25) and tin–boron codoping (SB25) enhance the structural resilience and electrochemical performance of LiNi0.9Mn0.05Co0.05O2 (NMC955) cathodes across a range of temperatures: −5 °C, 25 °C, and 45 °C. Both dopants integrate into the layered α-NaFeO2 structure, expanding lattice parameters and reducing cation mixing, while preserving particle morphology. At sub-ambient temperatures (−5 °C) where slow Li-ion transport is the primary limitation, Sn–B codoping delivers a 25% improvement in specific capacity at 500 mA g−1 relative to pristine NMC955, suppresses the emergence of a second high resistance charge transfer (RCT reduces from 717 Ω to 71.4 Ω), and maintains the highest exchange current densities, 0.3 A m−2. At 25 °C RCT is reduced, from 10.34 Ω in pristine NMC955 to 8.79 Ω, and the effective diffusion coefficient increases, from 1.5 to 1.6 × 10−12 cm−2 s−1, demonstrating enhanced low temperature transport kinetics. Long-term cycling at approximately 1C shows improved capacity retentions of 92.7% (B25) and 88.7% (SB25) after 100 cycles versus 78% for undoped NMC. Postmortem XPS/XAS confirm that codoping suppresses electrolyte-induced transition metal fluorination and CEI thickening, with Sn–B showing the smallest change in Ni oxidation state and local coordination after 200 cycles. Together, these results establish Sn–B co-doping as a scalable and effective strategy to simultaneously enhance the structural stability, interfacial chemistry, and low-temperature transport kinetics of Ni-rich NMC cathodes for demanding lithium-ion battery applications.
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Apr 2026
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Guangmeimei
Yang
,
Wei
Huang
,
Yifeng
Wang
,
Caiwu
Liang
,
Yuxiang
Zhou
,
Santosh
Kumar
,
Pilar
Ferrer Escorihuela
,
Parnia
Navabpour
,
Giuseppe
Sanzone
,
Trevor
Ferris
,
Georg
Held
,
Mark
Turner
,
Sarah J.
Haigh
,
Caterina
Ducati
,
Andreas
Kafizas
,
Reshma
Rao
Diamond Proposal Number(s):
[37550]
Open Access
Abstract: The scarcity of Ir presents a major challenge for scaling up its use as a water oxidation electrocatalyst in proton exchange membrane (PEM) water electrolysers. Developing conductive and stable supports is an effective way to reduce iridium loading while maintaining performance. However, the influence of support conductivity and stability on Ir-based catalytic activity remains poorly understood. The behaviour of the support is often obscured in conventional membrane electrode assembly (MEA) systems because IrOx itself is both highly conductive and exceptionally stable. To decouple support conductivity and passivation effects from the intrinsic conductivity of IrOx, we demonstrate a screening platform by studying a series of Ti-Nb alloy thin films produced by sputter deposition and investigate their performance as supports for IrOx water oxidation electrocatalysts. A range of electrochemical tests including accelerated stress tests (AST) were carried out on these samples, where characterisation techniques, including X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM), demonstrated the in situ formation of passivation layers on these supports during water oxidation. Our results suggest that a ~10 nm oxide passivation layer forms on metallic Ti-based supports. On alloying Nb with Ti metal, a more insulating rutile TiO2 phase forms during water oxidation whereas an anatase TiO2, with higher conductivity, is observed on the pure Ti support. Consequently, although alloying Ti with Nb improves the bulk conductivity, the structure of the oxide passivation layer results in a drastic decrease of conductivity and water oxidation activity. Our results demonstrate the importance of the structure and composition of surface oxide phases formed during water oxidation in controlling the overall stability and conductivity of support materials.
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Apr 2026
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Weiye
Ma
,
Lun
Zhang
,
Guanghan
Zhu
,
Hongrui
Kang
,
Haiyang
Yuan
,
Yongyi
Long
,
Zhiyi
Pan
,
Zhiqiang
Liu
,
Xiaojing
Liu
,
Jin
Liang
,
Yuxin
Liang
,
Zhenduo
Cui
,
Shengli
Zhu
,
Ying
Zhao
,
Zhonghui
Gao
Diamond Proposal Number(s):
[38100]
Open Access
Abstract: Poly(ethylene oxide) (PEO)-based electrolytes are promising for all-solid-state batteries but are typically limited to elevated temperatures due to PEO crystallinity and strong Li⁺–EO coordination. Here, we report a homogeneous PEO–LiTFSI electrolyte incorporating optimized Li3InCl6 that suppresses PEO crystallization, weakens Li⁺–TFSI⁻ coordination, and enhances Li-ion transport after acetonitrile solvent removal. This effect originates from the structural collapse of Li3InCl6 in acetonitrile, which exposes In3⁺ sites that preferentially adsorb TFSI⁻ anions, thereby disrupting the regular arrangement of PEO chains and inducing amorphization. In contrast to other oxide-based inorganic fillers, our results also found that the interface between PEO and Li3InCl6 enables efficient Li-ion transport. The resulting electrolyte achieves a high room-temperature ionic conductivity of 1.13×10⁻4 S cm-1 and excellent cycling stability with a LiNi0.8Co0.1Mn0.1O2 cathode, retaining 74 % capacity after 100 cycles at 0.3 C and 25 oC. To confirm the generality of this strategy and mechanism, we extended it to InCl3 and GaCl3 fillers, which similarly promoted amorphization in PEO–LiTFSI electrolytes. This work provides a general strategy to design amorphous polymer electrolytes for high-voltage solid-state batteries operating at room temperature.
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Apr 2026
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I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[30870]
Open Access
Abstract: Electrochemical flash sintering (EFS) is a newly developed, solvent-free technique for ultrafast (∼2 s) densification of lithium-containing solid-state battery materials. Unlike conventional flash sintering—which relies on uncontrolled thermal runaway and requires high electronic conductivity—EFS couples electronic conduction in mixed conductors with Li+ transport across interfaces with pure ionic conductors in composite or multilayer architectures. Using spatially resolved synchrotron total scattering and pair distribution function analysis, we elucidate the mechanisms of EFS, contrasting them with conventional flash sintering of single-phase materials. Under conventional conditions, Li3V2(PO4)3 (LVP) undergoes localized decomposition and cracking at low frequencies and high currents, while Li1.3Al0.3Ti1.7(PO4)3 (LATP) requires high frequencies to overcome blocking behavior—resulting in electrode melting, infiltration, and vitreous extrusion at the pellet perimeter. In contrast, EFS enables densification of LVP–LATP composites at lower frequencies that fail for either phase alone, with reactions confined to localized hotspots. In an LVP–LATP|LATP|LVP–LATP multilayer, decomposition products are more broadly distributed, including vanadium migration into the electrolyte; nonetheless, no preferential cracking or new phases were observed at electrode–electrolyte interfaces. These findings establish EFS as a viable one-step processing strategy for integrating (electro)chemically distinct phases and lay the groundwork for its broader adoption in the dry fabrication of solid-state electrochemical energy storage systems.
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Apr 2026
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I15-1-X-ray Pair Distribution Function (XPDF)
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Emily V.
Shaw
,
Javier
Pérez-Carvajal
,
Elena
López-Elvira
,
Shaoliang
Guan
,
Timothy
Lambden
,
Georgina P.
Robertson
,
Arad
Lang
,
Joonatan E. M.
Laulainen
,
Celia
Chen
,
Chumei
Ye
,
Anna
Herlihy
,
Catherine
Dejoie
,
David A.
Keen
,
Paul
Midgley
,
Thomas D.
Bennett
,
Celia
Castillo-Blas
Diamond Proposal Number(s):
[31401, 39316]
Open Access
Abstract: We report a scalable, water-based methodology for the direct room-temperature synthesis of porous amorphous UiO-66-type metal–organic frameworks (aMOFs), enabling the incorporation of a range of functionalised terepthalate linkers without organic solvents during framework formation. Powder X-ray diffraction and scanning electron diffraction confirm the formation of truly topologically amorphous UiO-66 derivatives, while pair distribution function (PDF) analysis shows that the amorphous frameworks retain the local structural motifs of their crystalline analogues despite the loss of long-range order. Relative to crystalline UiO-66, the directly synthesised amorphous UiO-66 exhibits a reduced but permanent porosity (BET surface area 286 vs. 997 m2 g−1 CO2-accessible pore volume 0.196 vs. 0.519 cm3 g−1), together with a high concentration of defects, consistent with a cluster[thin space (1/6-em)]:[thin space (1/6-em)]linker ratio of 1[thin space (1/6-em)]:[thin space (1/6-em)]5.3 compared with 1[thin space (1/6-em)]:[thin space (1/6-em)]6 for the ideal crystalline framework. In the esterification of levulinic acid, amorphous UiO-66 reaches 87.7% conversion to methyl levulinate after 3 h, compared with 75.5% for crystalline UiO-66, and retains 95% of its initial activity after five catalytic cycles (vs. 86% for the crystalline analogue). These results demonstrate that direct, water-based synthesis provides access to functional, porous, and highly defective amorphous UiO-66 materials with catalytic performance comparable to or exceeding that of their crystalline counterparts under the conditions studied.
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Mar 2026
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E02-JEM ARM 300CF
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Elif
Tezel
,
Beatrice
Garetto
,
Davide
Salusso
,
Dag K.
Sannes
,
Izar
Capel Berdiell
,
Sahra
Ahmed
,
Prantik
Sarkar
,
Stian
Svelle
,
Michael
Hirscher
,
Unni
Olsbye
,
Elisa
Borfecchia
,
Petra Ágota
Szilágyi
Diamond Proposal Number(s):
[41108]
Open Access
Abstract: This study investigates the catalytic performance of palladium nanoparticles supported on UiO-67, a zirconium-based metal–organic framework (MOF), for CO2 hydrogenation to methanol, emphasising the influence of the size and location of Pd particles in relation to the MOF matrix. Depending on the synthesis conditions, Pd particles were either supported on the outer surface of the MOF, forming larger nanoparticles (∼11–18 nm), or embedded within the MOF pores as smaller particles (∼1 nm), with their size constrained by the host framework. Advanced characterisation techniques, including X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and transmission electron microscopy (TEM), coupled with catalytic testing, revealed that Pd clusters embedded within the MOF exhibited higher CO2 conversion and methanol selectivity. This superior performance is attributed not only to the increased surface area-to-volume ratio of the smaller Pd clusters, but also to the enlarged metal–MOF interface, which promotes favourable electronic interactions and enhances the accessibility of active sites. Notably, the confined Pd clusters suppressed methane formation, producing CO as the sole by-product. Despite local distortions at elevated temperatures, the UiO-67 framework maintained its structural integrity under reaction conditions, highlighting its thermal and chemical robustness. These findings deepen the understanding of structure–activity relationships in MOF-based catalysts and underscore the critical role of precise control over metal dispersion and metal-support interfaces in optimising catalytic efficiency and selectivity for CO2 hydrogenation.
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Mar 2026
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