I13-2-Diamond Manchester Imaging
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Xuekun
Lu
,
Rhodri
Owen
,
Wenjia
Du
,
Zhenyu
Zhang
,
Antonio
Bertei
,
Roby
Soni
,
Xun
Zhang
,
Francesco
Iacoviello
,
Daqing
Li
,
Alice
Llewellyn
,
Jianuo
Chen
,
Han
Zhang
,
Xuhui
Yao
,
Qi
Li
,
Yunlong
Zhao
,
Shashidhara
Marathe
,
Christoph
Rau
,
Paul R.
Shearing
Diamond Proposal Number(s):
[29068]
Open Access
Abstract: Silicon is a promising negative electrode material for high-energy batteries, but its volume changes during cell cycling cause rapid degradation, limiting its loading to about 10 wt.% in conventional graphite/Si composite electrodes. Overcoming this threshold requires evidence-based design for the formulation of advanced electrodes. Here we combine multimodal operando imaging techniques, assisted by structural and electrochemical characterizations, to elucidate the multiscale electro-chemo-mechanical processes in graphite/Si composite negative electrodes. We demonstrate that the electrochemical cycling stability of Si particles strongly depends on the design of intraparticle nanoscale porous structures, and the encapsulation and loss of active Si particles result in excessive charging current being directed to the graphite particles, increasing the risk of lithium plating. We also show that heterogeneous strains are present between graphite and Si particles, in the carbon-binder domain and the electrode’s porous structures. Focusing on the volume expansion of the electrode during electrochemical cycling, we prove that the rate performance and Si utilization are heavily influenced by the expansion of the carbon-binder domain and the decrease in porosity. Based on this acquired knowledge, we propose a tailored double-layer graphite/Si composite electrode design that exhibits lower polarization and capacity decay compared with conventional graphite/Si electrode formulations.
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Oct 2025
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E02-JEM ARM 300CF
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Dengyang
Guo
,
Thomas A.
Selby
,
Simon
Kahmann
,
Sebastian
Gorgon
,
Linjie
Dai
,
Milos
Dubajic
,
Terry
Chien-Jen Yang
,
Simon M.
Fairclough
,
Thomas
Marsh
,
Ian E.
Jacobs
,
Baohu
Wu
,
Renjun
Guo
,
Satyawan
Nagane
,
Tiarnan A. S.
Doherty
,
Kangyu
Ji
,
Cheng
Liu
,
Yang
Lu
,
Taeheon
Kang
,
Capucine
Mamak
,
Jian
Mao
,
Peter
Muller-Buschbaum
,
Henning
Sirringhaus
,
Paul A.
Midgley
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[35894]
Open Access
Abstract: The high optoelectronic quality of halide perovskites makes them suitable for use in optoelectronic devices and, recently, in emerging quantum emission applications. Advancements in perovskite nanomaterials have led to the discovery of processes in which luminescence decay times are below 100 picoseconds, stimulating the exploration of even faster radiative rates for advanced quantum applications, which have only been realized in III–V materials grown using costly epitaxial growth methods. Here we discovered ultrafast quantum transients with timescales of around two picoseconds at low temperature in bulk formamidinium lead iodide films grown via scalable solution or vapour approaches. Using a multimodal strategy, combining ultrafast spectroscopy, optical and electron microscopy, we show that these transients originate from quantum tunnelling in nanodomain superlattices. The outcome of the transient decays, that is, photoluminescence, mirrors the photoabsorption of the states, with an ultranarrow linewidth at low temperature that can reach <2 nm (~4 meV). Localized correlation of the emission and structure reveals that the nanodomain superlattices are formed by alternating ordered layers of corner-sharing and face-sharing octahedra. This discovery opens new applications leveraging intrinsic quantum properties and demonstrates powerful multimodal approaches for quantum investigations.
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Oct 2025
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I19-Small Molecule Single Crystal Diffraction
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Milos
Dubajic
,
James R.
Neilson
,
Johan
Klarbring
,
Xia
Liang
,
Stephanie A.
Bird
,
Kirrily C.
Rule
,
Josie E.
Auckett
,
Thomas A.
Selby
,
Ganbaatar
Tumen-Ulzii
,
Yang
Lu
,
Young-Kwang
Jung
,
Cullen
Chosy
,
Zimu
Wei
,
Yorrick
Boeije
,
Martin V.
Zimmermann
,
Andreas
Pusch
,
Leilei
Gu
,
Xuguang
Jia
,
Qiyuan
Wu
,
Julia C.
Trowbridge
,
Eve M.
Mozur
,
Arianna
Minelli
,
Nikolaj
Roth
,
Kieran W. P.
Orr
,
Arman
Mahboubi Soufiani
,
Simon
Kahmann
,
Irina
Kabakova
,
Jianning
Ding
,
Tom
Wu
,
Gavin J.
Conibeer
,
Stephen P.
Bremner
,
Michael P.
Nielsen
,
Aron
Walsh
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[33123]
Open Access
Abstract: Lead halide perovskites have emerged as promising materials for solar energy conversion and X-ray detection owing to their remarkable optoelectronic properties. However, the microscopic origins of their superior performance remain unclear. Here we show that low-symmetry dynamic nanodomains present in the high-symmetry average cubic phases, whose characteristics are dictated by the A-site cation, govern the macroscopic behaviour. We combine X-ray diffuse scattering, inelastic neutron spectroscopy, hyperspectral photoluminescence microscopy and machine-learning-assisted molecular dynamics simulations to directly correlate local nanoscale dynamics with macroscopic optoelectronic response. Our approach reveals that methylammonium-based perovskites form densely packed, anisotropic dynamic nanodomains with out-of-phase octahedral tilting, whereas formamidinium-based systems develop sparse, isotropic, spherical nanodomains with in-phase tilting, even when crystallography reveals cubic symmetry on average. We demonstrate that these sparsely distributed isotropic nanodomains present in formamidinium-based systems reduce electronic dynamic disorder, resulting in a beneficial optoelectronic response, thereby enhancing the performance of formamidinium-based lead halide perovskite devices. By elucidating the influence of the A-site cation on local dynamic nanodomains, and consequently, on the macroscopic properties, we propose leveraging this relationship to engineer the optoelectronic response of these materials, propelling further advancements in perovskite-based photovoltaics, optoelectronics and X-ray imaging.
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Jun 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[35796]
Open Access
Abstract: Two-dimensional (2D) transition metal dichalcogenides have emerged as a promising platform for next-generation optoelectronic and spintronic devices. Mechanical exfoliation using adhesive tape remains the dominant method for preparing 2D materials of highest quality, including transition metal dichalcogenides, but always results in small-sized flakes. This limitation poses a significant challenge for investigations and applications where large scale flakes are needed. To overcome these constraints, we explored the preparation of 2D
WS
2
and
WSe
2
using a recently developed kinetic in situ single-layer synthesis method (KISS). In particular, we focused on the influence of different substrates, Au and Ag, and chalcogen atoms, S and Se, on the yield and quality of the 2D films. The crystallinity and spatial morphology of the 2D films were characterized using optical microscopy and atomic force microscopy, providing a comprehensive assessment of exfoliation quality. Low-energy electron diffraction verified that there is no preferential orientation between the 2D film and the substrate, while optical microscopy revealed that
WSe
2
consistently outperformed
WS
2
in producing large monolayers, regardless of the substrate used. Finally, X-ray diffraction and X-ray photoelectron spectroscopy demonstrate that no covalent bonds are formed between the 2D material and the underlying substrate. These results identify KISS method as a non-destructive method for a more scalable approach of high-quality 2D transition metal dichalcogenides.
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May 2025
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I06-Nanoscience (XPEEM)
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Diamond Proposal Number(s):
[27482]
Open Access
Abstract: We present a spectroscopic study of the magnetic properties of Fe3-δGeTe2 single crystals with varying Fe content, achieved by tuning the stoichiometry of the crystals. We carried out x-ray absorption spectroscopy and analyzed the x-ray circular magnetic dichroism spectra using the sum rules, to determine the orbital and spin magnetic moments of the materials. We find a clear reduction of the spin and orbital magnetic moment with increasing Fe deficiency. Magnetic susceptibility measurements show that the reduction in magnetization is accompanied by a reduced Curie temperature. Multiplet calculations reveal that the Fe2+ state increasingly mixes with a higher valence state when the Fe deficiency is increased. This effect is correlated with the weakening of the magnetic moment. As single crystals are the base material for exfoliation processes, our results are relevant for the assembly of 2D magnetic heterostructures.
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Jul 2024
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I14-Hard X-ray Nanoprobe
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Lucas Atila
Bernardes Marcal
,
Nils
Lamers
,
Susanna
Hammarberg
,
Zhaojun
Zhang
,
Huaiyu
Chen
,
Dmitry
Dzhigaev
,
Miguel
Gomez-Gonzalez
,
Julia
Parker
,
Alexander
Bjorling
,
Anders
Mikkelsen
,
Jesper
Wallentin
Diamond Proposal Number(s):
[25924]
Open Access
Abstract: Over the last years metal halide perovskites have demonstrated remarkable potential for integration in light emitting devices. Heterostructures allow for tunable bandgap depending on the local anion composition, crucial for optoelectronic devices, but local structural effects of anion exchange in single crystals is not fully understood. Here, we investigate how the anion exchange of CsPbBr3 nanowires fully and locally exposed to HCl vapor affects the local crystal structure, using nanofocused x-rays. We study the nanoscale composition and crystal structure as function of HCl exposure time and demonstrate the correlation of anion exchange with changes in the lattice parameter. The local composition was measured by x-ray fluorescence and x-ray diffraction, with general agreement of both methods but with much less variation using latter. The heterostructured nanowires exhibit unintentional gradients in composition, both axially and radially. Ferroelastic domains are observed for all HCl exposure times, and the magnitude of the lattice tilt decreases for higher Cl concentrations.
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Mar 2024
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B18-Core EXAFS
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Diamond Proposal Number(s):
[15151]
Abstract: Various techniques were employed to prepare a dual support system of CeZrO2 and H-ZSM-5 (80) including physically mixing, co-precipitation and sonochemical methods, which were followed by the deposition of bimetallic Pd and Pt via wet impregnation to obtain the final catalysts. The catalysts were tested in the total methane oxidation between 200 and 500 °C and the most active is the material derived from sonochemical synthesis. This catalyst achieved a remarkable methane conversion of 84% at a low temperature of 300 °C and high Gas Hourly Space Velocity (GHSV) of 100000 ml g−1 h−1. Characterisation using x-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), scanning transmission electron microscope (STEM), Energy-dispersive x-ray spectroscopy (EDS), temperature-programmed reduction (TPR) and x-ray absorption fine structure (XAFS) techniques revealed the intimate distribution of catalyst components and facile redox behaviour of both Pd and CeZrO2 components. The catalysts based on sonochemical CeZrO2 was proven to be relatively stable with only 7% methane conversion loss after 50 h continuously on stream at 300 °C compared to the corresponding 14% witnessed with the commercial TiO2-based material.
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Aug 2023
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I06-Nanoscience (XPEEM)
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O. J.
Amin
,
S. F.
Poole
,
S.
Reimers
,
L. X.
Barton
,
A.
Dal Din
,
F.
Maccherozzi
,
S. S.
Dhesi
,
V.
Novák
,
F.
Krizek
,
J. S.
Chauhan
,
R. P.
Campion
,
A. W.
Rushforth
,
T.
Jungwirth
,
O. A.
Tretiakov
,
K. W.
Edmonds
,
P.
Wadley
Diamond Proposal Number(s):
[26255, 27845]
Open Access
Abstract: Topologically protected magnetic textures are promising candidates for information carriers in future memory devices, as they can be efficiently propelled at very high velocities using current-induced spin torques. These textures—nanoscale whirls in the magnetic order—include skyrmions, half-skyrmions (merons) and their antiparticles. Antiferromagnets have been shown to host versions of these textures that have high potential for terahertz dynamics, deflection-free motion and improved size scaling due to the absence of stray field. Here we show that topological spin textures, merons and antimerons, can be generated at room temperature and reversibly moved using electrical pulses in thin-film CuMnAs, a semimetallic antiferromagnet that is a testbed system for spintronic applications. The merons and antimerons are localized on 180° domain walls, and move in the direction of the current pulses. The electrical generation and manipulation of antiferromagnetic merons is a crucial step towards realizing the full potential of antiferromagnetic thin films as active components in high-density, high-speed magnetic memory devices.
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May 2023
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I10-Beamline for Advanced Dichroism - scattering
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Diamond Proposal Number(s):
[21872, 27487]
Open Access
Abstract: The topological surface states (TSSs) in topological insulators (TIs) offer exciting prospects for dissipationless spin transport. Common spin-based devices, such as spin valves, rely on trilayer structures in which a non-magnetic (NM) layer is sandwiched between two ferromagnetic (FM) layers. The major disadvantage of using high-quality single-crystalline TI films in this context is that a single pair of spin-momentum locked channels spans across the entire film, meaning that only a very small spin current can be pumped from one FM to the other, along the side walls of the film. On the other hand, using nanocrystalline TI films, in which the grains are large enough to avoid hybridization of the TSSs, will effectively increase the number of spin channels available for spin pumping. Here, we used an element-selective, x-ray based ferromagnetic resonance technique to demonstrate spin pumping from a FM layer at resonance through the TI layer and into the FM spin sink.
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Mar 2023
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I19-Small Molecule Single Crystal Diffraction
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Haofan
Yang
,
Chao
Li
,
Tao
Liu
,
Thomas
Fellowes
,
Samantha Y.
Chong
,
Luca
Catalano
,
Mounib
Bahri
,
Weiwei
Zhang
,
Yongjie
Xu
,
Lunjie
Liu
,
Wei
Zhao
,
Adrian M.
Gardner
,
Rob
Clowes
,
Nigel D.
Browning
,
Xiaobo
Li
,
Alexander J.
Cowan
,
Andrew I.
Cooper
Abstract: Molecular packing controls optoelectronic properties in organic molecular nanomaterials. Here we report a donor–acceptor organic molecule (2,6-bis(4-cyanophenyl)-4-(9-phenyl-9H-carbazol-3-yl)pyridine-3,5-dicarbonitrile) that exhibits two aggregate states in aqueous dispersions: amorphous nanospheres and ordered nanofibres with π–π molecular stacking. The nanofibres promote sacrificial photocatalytic H2 production (31.85 mmol g−1 h−1) while the nanospheres produce hydrogen peroxide (H2O2) (3.20 mmol g−1 h−1 in the presence of O2). This is the first example of an organic photocatalyst that can be directed to produce these two different solar fuels simply by changing the molecular packing. These different packings affect energy band levels, the extent of excited state delocalization, the excited state dynamics, charge transfer to O2 and the light absorption profile. We use a combination of structural and photophysical measurements to understand how this influences photocatalytic selectivity. This illustrates the potential to achieve multiple photocatalytic functionalities with a single organic molecule by engineering nanomorphology and solid-state packing.
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Jan 2023
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