I15-1-X-ray Pair Distribution Function (XPDF)
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Adam F.
Sapnik
,
Philip A.
Chater
,
Dean S.
Keeble
,
John S. O.
Evans
,
Federica
Bertolotti
,
Antonietta
Guagliardi
,
Lise J.
Støckler
,
Elodie A.
Harbourne
,
Anders B.
Borup
,
Rebecca S.
Silberg
,
Adrien
Descamps
,
Clemens
Prescher
,
Benjamin D.
Klee
,
Axel
Phelipeau
,
Imran
Ullah
,
Kárel G.
Medina
,
Tobias A.
Bird
,
Viktoria
Kaznelson
,
William
Lynn
,
Andrew L.
Goodwin
,
Bo B.
Iversen
,
Celine
Crepisson
,
Emil S.
Bozin
,
Kirsten M. Ø.
Jensen
,
Emma E.
Mcbride
,
Reinhard B.
Neder
,
Ian
Robinson
,
Justin S.
Wark
,
Michał
Andrzejewski
,
Ulrike
Boesenberg
,
Erik
Brambrink
,
Carolina
Camarda
,
Valerio
Cerantola
,
Sebastian
Goede
,
Hauke
Höppner
,
Oliver S.
Humphries
,
Zuzana
Konopkova
,
Naresh
Kujala
,
Thomas
Michelat
,
Motoaki
Nakatsutsumi
,
Alexander
Pelka
,
Thomas R.
Preston
,
Lisa
Randolph
,
Michael
Roeper
,
Andreas
Schmidt
,
Cornelius
Strohm
,
Minxue
Tang
,
Peter
Talkovski
,
Ulf
Zastrau
,
Karen
Appel
,
David A.
Keen
Diamond Proposal Number(s):
[39017]
Open Access
Abstract: High-quality total scattering data, a key tool for understanding atomic-scale structure in disordered materials, require stable instrumentation and access to high momentum transfers. This is now routine at dedicated synchrotron instrumentation using high-energy X-ray beams, but it is very challenging to measure a total scattering dataset in less than a few microseconds. This limits their effectiveness for capturing structural changes that occur at the much faster timescales of atomic motion. Current X-ray free-electron lasers (XFELs) provide femtosecond-pulsed X-ray beams with maximum energies of ∼24 keV, giving the potential to measure total scattering and the attendant pair distribution functions (PDFs) on femtosecond timescales. We demonstrate that this potential has been realized using the HED scientific instrument at the European XFEL and present normalized total scattering data for 0.35 Å−1 < Q < 16.6 Å−1 and their PDFs from a broad spectrum of materials, including crystalline, nanocrystalline and amorphous solids, liquids and clusters in solution. We analyzed the data using a variety of methods, including Rietveld refinement, small-box PDF refinement, joint reciprocal–real-space refinement, cluster refinement and Debye scattering analysis. The resolution function of the setup is also characterized. We conclusively show that high-quality data can be obtained from a single ∼30 fs XFEL pulse for multiple different sample types. Our efforts not only significantly increase the existing maximum reported Q range for an S(Q) measured at an XFEL but also mean that XFELs are now a viable X-ray source for the broad community of people using reciprocal-space total scattering and PDF methods in their research.
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Sep 2025
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I16-Materials and Magnetism
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Diamond Proposal Number(s):
[36376, 37994]
Open Access
Abstract: We report the results of synchrotron Bragg Coherent X-ray Diffraction Imaging (BCDI) experiments to investigate domain formation in a micron-sized magnetite crystal undergoing the Verwey transition at low temperature. A strong splitting of the measured 311 Bragg reflection was observed in the low-temperature phase, indicating the formation of domains. BCDI revealed pronounced strain distributions, characterized by a clear layered stripe domain structure in real space. Stripes were seen only along the [001] crystallographic direction, normal to the substrate surface direction, breaking the symmetry of the cubic high-temperature phase. It is argued that other domain directions were suppressed by the sample mounting orientation. More surprisingly, only a single domain orientation was observed, suggesting an additional symmetry-breaking influence originating from the shape of the crystal. Gaining insight into how thermal effects induce the formation of layered or striped phases offers a valuable framework for understanding the development of mesoscopic domains and strain patterns in functional materials.
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Jul 2025
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I13-1-Coherence
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Diamond Proposal Number(s):
[33522]
Abstract: Cation alloying and substrate morphology control have proved to be effective in controlling strains in perovskite films by macroscale characterizations. However, the nanoscale characterizations of strains are still limited, which hinder the comprehensive understanding of the strain regulation. Here, the strain regulation of MAPbI3 (MA = CH3NH2) is done by Cs (Cesium) alloying and introduction of a nano-structured substrate to the perovskite films. Laboratory X-ray diffraction analysis shows that Cs alloying introduces compressive strain, whereas providing a nano-structured substrate introduces tensile strain. Bragg coherent X-ray diffraction imaging further demonstrates that nanoscale homogeneity of the strain in pure MAPbI3 would be destroyed through 3 at% Cs alloying, as the strain varies from compressive to tensile. Both compressive and tensile domains exist in the perovskite crystals at the same time. The application of a nano-structured substrate is found to cause the nanoscale heterogeneity of strains in the MAPbI3 films. The strain homogeneity caused by combining both 3% Cs alloying and providing a nano-structured substrate is found to enhance the structural stability of perovskite films. The results provide 3D nanoscale monitoring of strains for the purpose of strain regulation, which contributes to further understanding of the strains in perovskite materials.
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Jun 2025
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I16-Materials and Magnetism
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David
Yang
,
Ana F.
Suzana
,
Longlong
Wu
,
Sung Soo
Ha
,
Sungwook
Choi
,
Hieu Minh
Ngo
,
Muhammad Mahmood
Nawaz
,
Hyunjung
Kim
,
Jialun
Liu
,
Daniel
Treuherz
,
Nan
Zhang
,
Zheyi
An
,
Gareth
Nisbet
,
Daniel G.
Porter
,
Ian K.
Robinson
Diamond Proposal Number(s):
[30687, 33417, 34617, 28709]
Open Access
Abstract: Strontium titanate is a classic quantum paraelectric oxide material that has been widely studied in bulk and thin films. It exhibits a well-known cubic-to-tetragonal antiferrodistortive phase transition at 105 K, characterized by the rotation of oxygen octahedra. A possible second phase transition at lower temperature is suppressed by quantum fluctuations, preventing the onset of ferroelectric order. However, recent studies have shown that ferroelectric order can be established at low temperatures by inducing strain and other means. Here, we used in situ multireflection Bragg coherent x-ray diffraction imaging to measure the strain and rotation tensors for two strontium titanate microcrystals at low temperature. We observe strains induced by dislocations and inclusion-like impurities in the microcrystals. Based on radial magnitude plots, these strains increase in magnitude and spread as the temperature decreases. Pearson's correlation heat maps show a structural transition at 50 K, which could possibly be the formation of a low-temperature ferroelectric phase in the presence of strain. We do not observe any change in local strains associated with the tetragonal phase transition at 105 K.
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Jan 2025
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I13-1-Coherence
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Kieran W. P.
Orr
,
Jiecheng
Diao
,
Krishanu
Dey
,
Madsar
Hameed
,
Milos
Dubajic
,
Hayley L.
Gilbert
,
Thomas A.
Selby
,
Szymon J.
Zelewski
,
Yutong
Han
,
Melissa R.
Fitzsimmons
,
Bart
Roose
,
Peng
Li
,
Jiadong
Fan
,
Huaidong
Jiang
,
Joe
Briscoe
,
Ian K.
Robinson
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[31362]
Open Access
Abstract: Strain is an important property in halide perovskite semiconductors used for optoelectronic applications because of its ability to influence device efficiency and stability. However, descriptions of strain in these materials are generally limited to bulk averages of bare films, which miss important property-determining heterogeneities that occur on the nanoscale and at interfaces in multilayer device stacks. Here, we present three-dimensional nanoscale strain mapping using Bragg coherent diffraction imaging of individual grains in Cs0.1FA0.9Pb(I0.95Br0.05)3 and Cs0.15FA0.85SnI3 (FA = formamidinium) halide perovskite absorbers buried in full solar cell devices. We discover large local strains and striking intragrain and grain-to-grain strain heterogeneity, identifying distinct islands of tensile and compressive strain inside grains. Additionally, we directly image dislocations with surprising regularity in Cs0.15FA0.85SnI3 grains and find evidence for dislocation-induced antiphase boundary formation. Our results shine a rare light on the nanoscale strains in these materials in their technologically relevant device setting.
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May 2024
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I13-1-Coherence
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Kieran W. P.
Orr
,
Jiecheng
Diao
,
Muhammad Naufal
Lintangpradipto
,
Darren J.
Batey
,
Affan N.
Iqbal
,
Simon
Kahmann
,
Kyle
Frohna
,
Milos
Dubajic
,
Szymon J.
Zelewski
,
Alice E.
Dearle
,
Thomas A.
Selby
,
Peng
Li
,
Tiarnan A. S.
Doherty
,
Stephan
Hofmann
,
Osman M.
Bakr
,
Ian K.
Robinson
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[25097, 28495, 30308]
Open Access
Abstract: In recent years, halide perovskite materials have been used to make high performance solar cell and light-emitting devices. However, material defects still limit device performance and stability. Here, we use synchrotron-based Bragg Coherent Diffraction Imaging to visualise nanoscale strain fields, such as those local to defects, in halide perovskite microcrystals. We find significant strain heterogeneity within MAPbBr3 (MA = CH3NH3+) crystals in spite of their high optoelectronic quality, and identify both 〈100〉 and 〈110〉 edge dislocations through analysis of their local strain fields. By imaging these defects and strain fields in situ under continuous illumination, we uncover dramatic light-induced dislocation migration across hundreds of nanometers. Further, by selectively studying crystals that are damaged by the X-ray beam, we correlate large dislocation densities and increased nanoscale strains with material degradation and substantially altered optoelectronic properties assessed using photoluminescence microscopy measurements. Our results demonstrate the dynamic nature of extended defects and strain in halide perovskites, which will have important consequences for device performance and operational stability.
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Sep 2023
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Ralf F.
Ziesche
,
Thomas M. M.
Heenan
,
Pooja
Kumari
,
Jarrod
Williams
,
Weiqun
Li
,
Matthew E.
Curd
,
Timothy L.
Burnett
,
Ian
Robinson
,
Dan J. L.
Brett
,
Matthias J.
Ehrhardt
,
Paul D.
Quinn
,
Layla B.
Mehdi
,
Philip J.
Withers
,
Melanie
Britton
,
Nigel D.
Browning
,
Paul R.
Shearing
Open Access
Abstract: Demand for low carbon energy storage has highlighted the importance of imaging techniques for the characterization of electrode microstructures to determine key parameters associated with battery manufacture, operation, degradation, and failure both for next generation lithium and other novel battery systems. Here, recent progress and literature highlights from magnetic resonance, neutron, X-ray, focused ion beam, scanning and transmission electron microscopy are summarized. Two major trends are identified: First, the use of multi-modal microscopy in a correlative fashion, providing contrast modes spanning length- and time-scales, and second, the application of machine learning to guide data collection and analysis, recognizing the role of these tools in evaluating large data streams from increasingly sophisticated imaging experiments.
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May 2023
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Nigel D.
Browning
,
William
Bryan
,
James
Clarke
,
Michael
Ellis
,
Angus I.
Kirkland
,
Simon
Maskell
,
Julian
Mckenzie
,
B. Layla
Mehdi
,
R. J. Dwayne
Miller
,
Yoshie
Murooka
,
Timothy C. Q.
Noakes
,
Ian
Robinson
,
Sven L. M.
Schroeder
,
Jasper
Van Thor
,
Carsten
Welsch
Abstract: Transformative innovations in the science and technology of personalized medicine, energy storage, and clean growth start from achieving atomic and molecular understanding, and then control, of the fundamental (bio)-chemical interactions that determine each process. To generate the required level of understanding and control, the UK is currently investing in the design of a new national facility centered on the unique measurement capabilities offered by relativistic ultrafast electron diffraction and imaging (RUEDI). The underlying science and technology for RUEDI – ultrafast measurements and electron diffraction/imaging - are areas where John Spence made seminal contributions over the course of his career, and his work in these areas continues to guide the development of the science program for this new facility. Should RUEDI be successful in its goals, it will permit the direct observation of atomic/electronic motions directing the very chemistry we must control for the advances listed above.
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Aug 2022
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I13-1-Coherence
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Abstract: The human cell nucleus serves as an important organelle holding the genetic blueprint for life. In this work, X-ray ptychography was applied to assess the masses of human cell nuclei using its unique phase shift information. Measurements were carried out at the I13-1 beamline at the Diamond Light Source that has extremely large transverse coherence properties. The ptychographic diffractive imaging approach allowed imaging of large structures that gave quantitative measurements of the phase shift in 2D projections. In this paper a modified ptychography algorithm that improves the quality of the reconstruction for weak scattering samples is presented. The application of this approach to calculate the mass of several human nuclei is also demonstrated.
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Jul 2021
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I13-1-Coherence
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Open Access
Abstract: Studies of the structural and functional role of chromosomes in cytogenetics have spanned more than 10 decades. In this work, we take advantage of the coherent X-rays available at the latest synchrotron sources to extract the individual masses of all 46 chromosomes of metaphase human B and T cells using hard X-ray ptychography. We have produced ‘X-ray karyotypes’ of both heavy metal–stained and unstained spreads to determine the gain or loss of genetic material upon low-level X-ray irradiation doses due to radiation damage. The experiments were performed at the I-13 beamline, Diamond Light Source, Didcot, UK, using the phase-sensitive X-ray ptychography method.
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Mar 2021
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