I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[38563]
Open Access
Abstract: The development of diverse battery chemistries demands advanced diagnostic techniques to study them. Neutron diffraction, which is sensitive to light elements and capable of distinguishing transition metals with similar electronic configurations, is well-suited to probe crystallographic transformations in battery materials and their degradation pathways. Yet its use has been limited by compromised data quality, low time resolution, and the absence of resource-efficient, reproducible, benchmarked electrochemical cells. Here, using the high-resolution cold-neutron diffractometer WISH, we demonstrate operando neutron diffraction studies of standard laboratory-scale single-layer pouch cells without build modifications, electrolyte deuteration, or isotope enrichment of the electrodes, under practical cycling conditions. This expands the battery diagnostic toolkit beyond X-rays and enables academic exploration of both established and emerging technologies, especially lithium–metal, anode-less, and lithium–sulfur batteries.
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Mar 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[19850, 29271]
Open Access
Abstract: Understanding the active site dynamics and redox behavior of copper species in zeolite catalysts is critical for advancing the understanding of catalytic methane-to-methanol conversion. These catalysts are also used for the selective catalytic reduction of NOx in diesel engines. Here, we present the first application of muon spin spectroscopy (μSR) to study transition metal-exchanged SSZ-13 (Cu-SSZ-13) zeolites and highlight the potential of μSR. This technique reveals unique insights into the local magnetic and electronic environments of Cu species, inaccessible via conventional spectroscopies. Temperature-dependent transverse field μSR measurements show a clear conversion of paramagnetic muonium (Mu0) to diamagnetic muon (Mu+) states, with distinct differences between Cu-loaded and pure SSZ-13 systems. This transformation is thermally activated, with Arrhenius analysis yielding activation energies of ∼3.3–5 meV, consistent with ionization processes of shallow donor states. Longitudinal field measurements confirm 2D muonium diffusion within Cu-SSZ-13 and support a model where muonium reacts with mono(μ-oxo)dicopper species, inducing comproportionation (2Cu2+ → 2Cu1.5+). DFT simulations validate this mechanism, reproducing the experimentally determined hyperfine coupling constants. At low temperatures (≤25 K), μSR also detects the onset of static magnetism in Cu clusters, consistent with Cu(II)-based multinuclear motifs. These results establish μSR as a powerful, underutilized probe for catalytic systems and provide compelling evidence for a multistep oxidation mechanism involving the initial reduction of Cu centers prior to methanol formation. This approach opens new avenues for real-time, local investigation of redox-active catalytic materials.
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Mar 2026
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I11-High Resolution Powder Diffraction
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Haowen
Tian
,
Li
Tianyu
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Anya S.
Mulligan
,
Jack P. G.
Tregidga
,
Matthew A.
Wright
,
Zohar
Arava
,
Chezhiyan
Aditya
,
Molleigh B.
Preefer
,
Stone
Kevin H
,
Jerry
Hu
,
Guang
Wu
,
Alicia María
Manjón-Sanz
,
Saul H.
Lapidus
,
John W.
Harter
,
Anthony K.
Cheetham
,
Ram
Seshadri
Diamond Proposal Number(s):
[36397]
Abstract: A previously unreported low-temperature phase transition in bismuth halide double perovskite Cs2AgBiCl6 is reported, thereby establishing trends in the structural ground states across Cs2NaBiCl6, Cs2AgBiCl6, and Cs2AgBiBr6. Using the combined toolkit of variable-temperature synchrotron X-ray and neutron powder diffraction, Raman spectroscopy, and density-functional theory-based electronic structure modeling, we demonstrate a cubic
𝐹𝑚3¯𝑚→
tetragonal I4/m transition upon cooling with distinct onset temperatures. Neutron powder diffraction refinements and DFT calculations assign the low-temperature phase of Cs2NaBiCl6 to I4/m, rather than the previously reported I4/mmm ground state. Cs2AgBiCl6 is also found to transform to a structure crystallizing in the I4/m space group at low temperatures. Temperature-dependent Raman data and density-functional-theory-based modeling capture the softening and freezing of octahedral tilt modes and quantify relative instabilities. Solid-state nuclear magnetic resonance spectroscopy at room temperature completes the characterization and helps underpin the subtle differences in the covalency across the compounds. Trends in the phase transition temperature Ts and tilt magnitudes emerge from coupled effects of halide identity, M(I)–site bonding character, and a mismatch between interatomic distances. These results establish the structure–dynamics–bonding framework for tuning tilt-driven instabilities in halide double perovskites.
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Mar 2026
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I19-Small Molecule Single Crystal Diffraction
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Cara J.
Hawkins
,
Batoul
Almoussawi
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Jan P.
Scheifers
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Manel
Sonni
,
Aeshah A.
Almushawwah
,
Troy D.
Manning
,
Marco
Zanella
,
Craig M.
Robertson
,
Luke M.
Daniels
,
Tim D.
Veal
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[36629]
Open Access
Abstract: The exploration of higher-dimensional chemical phase spaces and the synthesis of novel compounds can be achieved by applying a multiple-anion approach to materials discovery. The ability to combine and tune the stoichiometry of anions in a material can enable enhanced control of both the physical and electronic structures, providing a strategy for the modification of the properties of new materials being developed for a variety of applications, including solar absorbers and thermoelectrics. Here, we report the synthesis of Cu7.62Bi6Se12Cl6I, a quadruple-anion (Se2–, (Se2)2–, Cl–, I–) material within the Cu–Bi–Se–Cl–I phase space. Crystal growth reactions yield black, needle-like crystals, which exhibit a highly anisotropic and complex structure containing the four distinct anion types, solved from single-crystal X-ray diffraction data. Compositional analysis confirms the complex material stoichiometry, and a low band gap of 0.94(5) eV is measured to understand the potential for solar-absorbing applications. Cu7.62Bi6Se12Cl6I has a low thermal conductivity of 0.25(2) W K–1 m–1, which is attributed to multiple structural features via analysis of experimental heat capacity data and is achieved through the diversity in bonding that is accessed through the combination of four different types of anion.
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Feb 2026
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Open Access
Abstract: The evolution of buried interfaces, the hidden junctions where distinct phases exchange charge, mass, and mechanical response under nonequilibrium conditions, strongly influences the performance and stability of functional devices such as batteries, but they remain difficult to probe directly. This perspective summarizes the types of buried interfaces that form within battery electrodes and their electrochemical function in the device, and it discusses how advances in operando probes, cell architectures, and multimodal and correlative strategies have enabled dynamic and chemically specific visibility of their evolution. Despite this progress, operando signals remain challenging to interpret because they are affected by, for example, beam damage-induced changes, variations in operando cell geometry, and intrinsic sample-to-sample differences, which together limit quantitative insight. Building on these considerations, the perspective examines how operando visibility can be transformed into quantitative diagnosis by integrating multimodal measurements with physically informed interface models and data-driven analysis. The final section outlines a roadmap for reproducible and quantitative operando analysis, centered on standardized cell architectures, long-term autonomous measurements, and artificial intelligence approaches that incorporate physical constraints. In summary, these developments define a pathway from operando visibility to quantitative diagnosis and provide a foundation for advancing interface characterization and quantitative analysis in batteries and related energy materials.
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Feb 2026
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I11-High Resolution Powder Diffraction
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Amelia
Reach
,
Matthew
Wright
,
Anya S.
Mulligan
,
Zhengwu
Fang
,
Kang-Ting
Tseng
,
Cathy
Wang
,
Jerry G.
Hu
,
Miaofang
Chi
,
Anthony K.
Cheetham
,
Ram
Seshadri
,
Jeff
Sakamoto
Diamond Proposal Number(s):
[36397, 41364]
Abstract: NaSICONs, or sodium superionic conductors, are promising solid electrolyte materials for Na-based all-solid-state and aqueous redox-flow battery applications. Here, the composition Na3.4Zr2Si2.4P0.6O12 has been prepared through solution-assisted microwave processing and densification through rapid induction hot pressing. The samples display remarkably high total ionic conductivities between 7 and 9 mS cm–1, competitive with liquid electrolytes. A combination of synchrotron X-ray and neutron diffraction, electrochemical impedance spectroscopy, and variable-temperature solid-state nuclear magnetic resonance studies reveals rapid Na-ion transport through the rigid skeletal framework of this solid ion conductor. Variable-temperature synchrotron X-ray diffraction reveals structural phase separation in this composition on cooling at temperatures close to 430 K with the samples at room temperature displaying a mix of monoclinic C2/c and rhombohedral R3̅c components that appear to collectively contribute to the high conductivity. The observation of very high ionic conductivity in a region of compositional space that is associated with structural instability is proposed as a design principle for superionic conduction.
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Feb 2026
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E02-JEM ARM 300CF
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Jaeho
Lee
,
Wengang
Huang
,
Xiangyi
Zha
,
Xuemei
Li
,
Zixi
Xie
,
Peng
Chen
,
Chenghan
Sun
,
Muhammad Yazid
Bin Zulkifli
,
Sang T.
Pham
,
Bun
Chan
,
Marija
Švegovec
,
Atul
Shukla
,
Junyong
Zhu
,
Rijia
Lin
,
Nicholas M.
Bedford
,
Vicki
Chen
,
Sean
Collins
,
Andraž
Krajnc
,
Anthony K.
Cheetham
,
Lianzhou
Wang
,
Jingwei
Hou
Diamond Proposal Number(s):
[26822]
Open Access
Abstract: Developing quantum dots (QDs) with robust and stable photoluminescence are critical for the advancement of optical nanomaterials. However, QD synthesis still usually involves complex nucleation, growth, surface capping, and separation procedures. Herein, we present an approach to generating embedded PbI2 QDs in situ within the matrix of a metal–organic framework (MOF) glass. This is achieved by controllable decomposition of an optoelectronically inactive δ-phase organic lead halide perovskite (OLHP) within the MOF glass, where the high-temperature MOF melt alters the degradation pathway through interfacial bonding and dissolution effects, effectively preventing PbI2 aggregation and passivating the resulting QDs. The resulting composite exhibits high-quality, narrow line width photoluminescence at room temperature, alongside remarkable stability under ambient conditions. This innovative approach offers a sustainable and efficient route for QD generation, underscoring the potential of MOF glass-based composites in optoelectronic applications.
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Jan 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[34446]
Open Access
Abstract: Understanding the redox behavior and structural stability of aliovalent substituents in ionic conductors is critical, as their variable oxidation states can inadvertently introduce electronic conductivity and alter transport mechanisms under different atmospheric conditions. Here, we report the atmosphere-dependent redox behavior and local coordination of Mo in LaNb0.9Mo0.1O4.05, focusing on its influence on phase transition and transport properties, where the as-sintered LaNb0.9Mo0.1O4.05 was systematically annealed under pure O2, pure N2, vacuum (∼1.6 × 10–8 mbar), and 5% H2/N2 at 800 °C for different dwell times. Electron paramagnetic resonance (EPR) spectroscopy results demonstrate the emergence of Mo5+ under 5% H2/N2. In situ X-ray absorption near edge structure (XANES) measurements reveal the reversible redox behavior of Mo, where Mo5+ formed under 5% H2/N2 reoxidizes to Mo6+ upon exposure to static air, while complementary in situ extended X-ray absorption fine structure (EXAFS) analysis shows that the Nb coordination environment also transitions from prototypical LaNbO4 structure under reducing conditions back to the Mo-substituted LaNbO4 structure upon reoxidation. This change of the oxidation states of Mo could correspondingly alter the band structure of the sample, which further enhances charge transport: the sample annealed in 5% H2/N2 for 24 h exhibits a reduced activation energy and increased electronic conductivity. These results highlight a strong coupling among substituent redox flexibility, local structure, and transport properties, providing an understanding of tailoring the properties of ionic conductors through controlled redox environments.
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Dec 2025
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Jonathan R.
Thurston
,
Shuya
Li
,
Qi
Sun
,
Dennis
Nordlund
,
Luis
Kitsu Iglesias
,
Collin
Sindt
,
Santosh
Kumar
,
David C.
Grinter
,
Hong
Li
,
Ann L.
Greenaway
,
Elisa M.
Miller
,
Michael F.
Toney
Diamond Proposal Number(s):
[35956]
Abstract: P(NDI2OD-T2), commonly referred to as N2200, stands out as a promising electron-transporting (n-type) polymer for low-cost, flexible (photo)electrochemical applications due to its reversible two-electron reduction and high electron mobility. UV–vis spectroelectrochemistry in the tetrabutyl ammonium hexafluorophosphate/acetonitrile electrolyte shows two sets of chemically reversible redox signals in the cyclic voltammetry corresponding to the reduction of the neutral polymer film to polaronic and bipolaronic species. These electrochemical signatures suggest a distinct electronic reorganization upon reduction (polaron/bipolaron formation), highlighting the need for molecular-level insights into how charges are accommodated within the polymer backbone. While it has been previously hypothesized that charge predominantly localizes on the naphthalene diimide (NDI) unit during reductive charging, specific changes in atomic environments that confirm this localization have not been characterized in n-type polymers. Herein, we use near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to probe electronic transitions in an electrochemically charged polymer to deduce charge localization. The O K-edge (1s) spectra exhibit two distinct π* peaks; the intensity of the lower-energy π*a peak that corresponds to an excitation to a largely localized carbonyl state decreases with reductive potentials relative to the higher-energy π*b peak. We corroborate this with Raman spectroscopy at different potentials, which shows a decrease in intensity on the C–C/C═C and C═O stretching bands of NDI as well as a red shift of the carbonyl band due to the formation of a polaron on the NDI. Additionally, new Raman active NDI signals associated with elongated C═O and C═C bonds are observed at lower energy during the formation of charged states. Together with theoretical calculations, these findings show that the injected charge spatially localizes on the NDI units and is dominantly distributed on the carbonyl groups. The combination of NEXAFS, optical and vibrational spectroscopies, and theoretical calculations is generalizable to other pi-conjugated polymers and can identify charge localization for the further development of organic semiconductors.
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Oct 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[28349, 34243]
Open Access
Abstract: Ba2GdNbO6 has previously been reported to adopt either monoclinic, tetragonal, or cubic symmetry at room temperature. Using high-resolution synchrotron X-ray diffraction, neutron diffraction and neutron pair distribution function analysis we find that the compound adopts a tetragonal I4/m double-perovskite structure at room temperature (with a weak, temperature-independent second-order Jahn–Teller distortion in the NbO6 octahedra) and undergoes a phase transition to a monoclinic P21/n symmetry upon cooling to 2.4 K. Only upon heating above room temperature to T ≈ 450 K does Ba2GdNbO6 reversibly transition to a cubic Fm3̅m symmetry. Magnetic susceptibility measurements indicate predominant paramagnetic behavior down to 1.8 K, with minimal ferromagnetic short-range correlations (θ = 0.20(5) K) and a small exchange interaction (J1 = −0.0032(8) K). At 2 K and 9 T, the compound exhibits a maximum magnetic entropy change of −ΔSm = 15.75 J K–1 mol–1 and an adiabatic temperature change of ΔTad = 21 K, making it a promising candidate for low-temperature magnetocaloric applications. Heat capacity measurements confirm a rigid crystal lattice (TD = 267(3) K) and a corresponding small lattice entropy contribution in the low-temperature regime, highlighting the potential of Ba2GdNbO6 for effective cooling capability in magnetocaloric devices at cryogenic temperatures. This study elucidates the structural and magnetic characteristics of Ba2GdNbO6 and attests to its promise for low-temperature magnetocaloric refrigeration.
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Oct 2025
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