I08-1-Soft X-ray Ptychography
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Richard J.
Harrison
,
Jeffrey
Neethirajan
,
Zhaowen
Pei
,
Pengfei
Xue
,
Lourdes
Marcano
,
Radu
Abrudan
,
Emilie
Ringe
,
Po-Yen
Tung
,
Venkata S. C.
Kuppili
,
Burkhard
Kaulich
,
Benedikt J.
Daurer
,
Luis Carlos
Colocho Hurtarte
,
Majid
Kazemian
,
Liao
Chang
,
Claire
Donnelly
,
Sergio
Valencia
Diamond Proposal Number(s):
[33254]
Open Access
Abstract: Giant magnetofossils are unusual, micron-sized biogenic magnetite particles found in sediments dating back at least 97 million years. Their distinctive morphologies are the product of biologically controlled mineralisation, yet the identity of their biomineralising organism, and the biological function they serve, remain a mystery. It is currently thought that the organism exploited magnetite’s mechanical properties for protection. Here we explore an alternative hypothesis, that it exploited magnetite’s magnetic properties for the purpose of magnetoreception. We present a three-dimensional magnetic vector tomography study of a giant magnetofossil and assess its magnetoreceptive potential. Our results reveal a single magnetic vortex that displays an optimised response to spatial variations in the intensity of Earth’s magnetic field. This magnetic trait may have conferred an evolutionary advantage to mobile marine organisms, providing an upper age limit on the development of navigational magnetoreception and raising the possibility that earlier evidence of this sense may yet be preserved in the fossil record. More broadly, this work provides a blueprint for assessing the morphological and magnetic evidence for putative biogenic iron oxide particles, which are a key component in the search for early life on Earth and Mars.
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Oct 2025
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I13-1-Coherence
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Emily C.
Bamber
,
Fabio
Arzilli
,
Silvia
Cipiccia
,
Darren J.
Batey
,
Giuseppe
La Spina
,
Margherita
Polacci
,
Ali
Gholinia
,
Heath
Bagshaw
,
Danilo
Di Genova
,
Richard
Brooker
,
Daniele
Giordano
,
Pedro
Valdivia
,
Mike R.
Burton
Diamond Proposal Number(s):
[23863]
Open Access
Abstract: Nanoscale crystals are becoming increasingly recognised in the products of volcanic eruptions, spanning a range of magma compositions. The crystallisation of nanolites impacts magma rheology, ascent dynamics, and eruptive style. Their impact can be enhanced due to their capacity to aggregate and develop neighbouring chemically differentiated boundary layers. However, their 3D interaction, spatial distribution, and morphology is not currently understood. Here we present a cutting-edge, 3D nanometre-scale visualisation and quantification of nanolites in scoriae of the Las Sierras-Masaya basaltic Plinian eruptions, acquired using X-ray ptychography. We find that Ti-magnetite nanolites aggregate, forming elongate, irregular structures in 3D. Their crystallisation extracts Fe and Ti from the melt, resulting in differentiated boundary layers with higher viscosity. Syn-eruptive crystallisation of nanolites and their interaction is estimated to have increased magma viscosity by 2–3 orders of magnitude, therefore, they likely had a strong control on magma rheology, increasing the potential of magma fragmentation.
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Aug 2025
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I13-1-Coherence
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Diamond Proposal Number(s):
[23967]
Open Access
Abstract: How pigment distribution influences the cuticle density within a microscopic butterfly wing scale, and how both impact each scale’s final reflected color, remains unknown. We use ptychographic X-ray computed tomography to quantitatively determine, at nanoscale resolutions, the three-dimensional mass density of scales with pigmentation differences. By comparing cuticle densities between two pairs of scales with pigmentation differences, we determine that the density of the lower lamina is inversely correlated with pigmentation. In the upper lamina structure of Junonia orithya and Bicyclus anynana, low pigment levels also correlate with sheet-like chitin structures as opposed to rod-like structures. Within each scale, we determine that the lower lamina in all scales has the highest density, and distinct layers within the lower lamina help explain reflected color. We hypothesize that pigments, in addition to absorbing specific wavelengths, can affect cuticle polymerization, density, and refractive index, thereby impacting reflected wavelengths that produce colors.
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Aug 2025
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I13-1-Coherence
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Diamond Proposal Number(s):
[29218, 23409, 32637, 34164]
Abstract: In conventional x-ray ptychography, diffraction data are collected by scanning a sample through a monochromatic and spatially coherent x-ray beam. A high-resolution image is then retrieved using an iterative algorithm. Combined with a scan of the incident photon energy, it is also possible to access chemical and elemental information. Although powerful, the high brilliance required currently constrains the method to third and fourth generation synchrotron sources and long scanning times. An alternative approach is to use broadband illumination in combination with an energy resolving detector. These detectors record the data in a series of energy channels simultaneously, creating stacks of coherent data suitable for a ptychographic reconstruction. This approach promises to unlock the full power of the radiation source and provide spectral imaging at a higher rate and in a single acquisition. However, these detectors currently saturate well below reaching the flux rates produced at synchrotrons, which is preventing the uptake of this approach. Furthermore, current monochromatic synchrotron setups typically employ Fresnel zone plates for pre-sample focusing due to their stability, flexibility, and affordability, but these diffractive optics limit the spectral bandwidth that the setup can accept. In this article, we analyze the problem and consider alternative optics that can both maximize the total photon detection rates and broaden the tolerable bandwidth. Broadband x-ray ptychography has the potential to dramatically reduce data collection times at synchrotron sources but also to harness the full power of lower brilliance sources and transition x-ray ptychography into a laboratory technique.
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Aug 2025
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I08-1-Soft X-ray Ptychography
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Abstract: The scales of butterflies display a vast array of vivid colors. However, the exact mechanisms behind these colours are not yet fully understood. Butterfly scales consist of intricate nanostructures that in- teract with light through interference, diffraction, and scattering. Additionally, the nanostructures on butterfly scales vary in pigment density across different species.
A combination of 'pigment effects' and ‘structural effects’ gives rise to the vivid colors observed on a butterfly’s wings. Variations in pigment density have been correlated with specific nanostructures. However, the interplay between pigmentation and nanostructures - how they influence each other - remains largely unexplored. Hence, our work aims to perform a detailed examination of the distribution of various matrix components within butterfly scales, leading to a deeper understanding of not only their colour, but also their role in guiding nano- structure growth.
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Jul 2025
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I16-Materials and Magnetism
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Diamond Proposal Number(s):
[36376]
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):
[34164]
Open Access
Abstract: X-ray ptychography is a robust microscopy technique with nanoscale resolution that requires a spatially and temporally coherent illumination. In a typical setup, the temporal coherence requirements are satisfied by monochromating the x-ray source, e.g., using a crystal monochromator. Recent studies have shown that energy resolving, or hyperspectral, detectors can to some extent replace the role of the monochromator to perform, e.g., edge-subtraction ptychographic imaging with broadband radiation in a single acquisition. Scaling this capability from two dimensions (2D) to three dimensions (3D), and from a single absorption edge to multiple edges, is critical for its applications in structural and elemental characterisation. The method is hitherto limited by the inherently lower maximum count rate of hyperspectral detectors and the chromaticity of the optics often used in x-ray ptychography experiments, namely Fresnel zone plates. In this work, we design an optimized broadband spectroscopic ptychography setup and use it to perform 3D hyperspectral imaging of particles of battery material containing various percentages of nickel, manganese, cobalt (NMC). We show that we can identify different compositions based on their spectral response. We discuss the results and provide guidelines for future exploitation of the method in laboratory settings.
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Jun 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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I13-1-Coherence
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E.
Erin
,
L.
Fardin
,
D.
Batey
,
M.
Burian
,
S.
Vogel
,
S.
Grimm
,
M.
Fratini
,
M.
Palombo
,
F.
Zhou
,
G. J. M.
Parker
,
A.
Olivo
,
S.
Cipiccia
Diamond Proposal Number(s):
[34189, 32306]
Open Access
Abstract: X-ray ptychography is a scanning coherent diffraction imaging technique which combines nanometer-scale resolution with high penetration depth. This method has been proven to be suitable for scanning weakly absorbing samples and therefore potentially very valuable for medical applications such as brain imaging. However, currently employed scanning techniques present challenges: step-scanning is too slow and inefficient, while fly-scanning introduces blurring and noise into reconstructions due to the motion and reduced photon counts per pixel. To date, only a few methods have been proposed to denoise reconstructions, most of which rely on traditional approaches and are limited in addressing the challenges posed by noise and blurring. To overcome these limitations, we investigate the possibility of using a deep learning-based denoising method combined with position binning. The deep learning-based denoising method, Deep Image Prior (DIP), denoises the reconstructions while position binning increases the photon count statistics per pixel. The method can be integrated within the existing iterative phase retrieval algorithms to denoise the object or probe in between iterations. The method is tested in far-field geometry on two different samples: a Siemens star resolution target and a polymer-based phantom mimicking the white matter of the brain. By assessing the resolution via Fourier ring correlation, we measure up to a 14% increase in the resolution. However, depending on the architecture used, artifacts due to machine hallucination appear in the denoised images which could be affecting the observed enhancement in resolution. This will be the subject of further investigation.
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May 2025
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I13-1-Coherence
I16-Materials and Magnetism
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Abstract: The performance and longevity of lithium-ion batteries depend critically on the structural and electrochemical dynamics of their constituent materials, particularly cathodes. Among these, LiCoO2 (LCO) is a benchmark material known for its high energy density. However, the structural evolution of LCO during electrochemical cycling, including strain, defects, and domain formation, remains poorly understood, largely due to the limitations of conventional imaging techniques in resolving nanoscale dynamics non-destructively.
This thesis leverages Bragg Coherent X-ray Diffraction Imaging (Bragg CDI), a powerful, non-destructive technique, to probe the three-dimensional structural and strain dynamics of nanocrystalline LCO cathodes. By combining traditional phasing methods with machine learning-based strain reconstruction tools, and further enhancing data interpretation with advanced analysis techniques, this work provides unprecedented insights into the nanoscale behaviour of LCO under varying electrochemical and electric field conditions.
The study reveals that during electrochemical cycling, LCO nanocrystals exhibit dynamic domain behaviour, including the formation and expansion of domains at the crystal edges in the charged state, followed by fragmentation into smaller domains bounded by dislocations. These processes are reversed during discharge, with domains shrinking and reassembling as the crystal approaches its discharged state. Additionally, under applied electric fields, polarised domains and significant phase changes are observed, with the field inducing phase uniformity along its direction. Notably, a migrating dislocation near the crystal edge exhibits depth invariance across varying field magnitudes, aligning with the domain expansion limit observed during cycling.
These findings contribute to a deeper understanding of the structural and electrochemical interplay in LCO cathodes, offering valuable insights into the mechanisms underlying performance degradation and suggesting pathways for improving battery design and functionality.
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May 2025
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