I15-Extreme Conditions
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Diamond Proposal Number(s):
[36011, 39563]
Abstract: This study identifies the structural origin of giant electrostrain in samarium-doped bismuth ferrite lead titanate (0.55Bi1-xSmxFeO3–0.45PbTiO3) ceramics. A giant peak-to-peak electrostrain (∼0.5 % at 60 kV cm–1) was obtained for compositions with x = 0.20 (20Sm) during initial poling, superior to Pb(Zr,Ti)O3 based ceramics with similar phase transition temperature of 275 °C, coupled with a piezoelectric coefficient of 276 pC/N comparable with hard PZT. While 20Sm is a macroscopically pseudo-cubic relaxor in its unpoled state, an irreversible, field-induced transformation gives a tetragonal (c/a∼1.115) ferroelectric phase as revealed by in-situ poling synchrotron X-ray diffraction and confirmed by transmission electron microscopy. The field-induced domain structure of the tetragonal structure could be reversibly switched under AC field after transformation. Quantitative strain analysis confirmed that the structural transformation accounts for approximately half of the total electrostrain, with the remainder by domain switching. These results highlight the importance of field-induced structural transformations for the development of high-performance piezoelectrics.
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Sep 2026
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B18-Core EXAFS
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Abstract: Dual-atom catalysts (DACs) surpass the limitations of single-atom catalysts by harnessing synergy between adjacent metal sites. Herein, we propose a novel strategy employing d-p orbital synergistic modulation in Fe-Sb DACs. Combined density functional theory and molecular dynamics simulations reveal that the significant d-p orbital synergistic regulation between Fe and Sb sites promotes O2 adsorption and activation, lowers the energy barrier for Osingle bondO bond cleavage, and optimizes water desorption. As a proof-of-concept, Fe/Sb DACs anchored on a nitrogen-doped carbon matrix (Fe/Sb-N-C) were synthesized. The atomic-level local coordination of Fe-Sb dual atoms was systematically characterized by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption fine structure (XAFS) analyses. The as-fabricated Fe/Sb-N-C exhibits exceptional alkaline oxygen reduction reaction (ORR) performance, featuring a half-wave potential of 0.92 V and outstanding durability. Aqueous Zn-air batteries equipped with Fe/Sb-N-C achieve a high maximum power density of 196 mW cm-2 and a specific capacity of 795 mAh g-1. Furthermore, quasi-solid-state Zn-air batteries demonstrate wide-temperature operability (-30 to 60 °C) and stability under high current densities. This work establishes d-p orbital synergy as a new paradigm for designing high-efficiency ORR catalysts, broadening their application in energy devices across extreme temperatures.
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Sep 2026
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DIAD-Dual Imaging and Diffraction Beamline
E02-JEM ARM 300CF
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Kang
Xiang
,
Yueyuan
Wang
,
Shi
Huang
,
Hongyuan
Song
,
Alberto
Leonardi
,
Peter
Garland
,
Sharif
Ahmed
,
Michał M.
Kłosowski
,
Hongmei
Yang
,
Mengnie
Li
,
Jiawei
Mi
Diamond Proposal Number(s):
[31637, 35828]
Open Access
Abstract: Using quasi-simultaneous synchrotron X-ray diffraction and tomography techniques, we have studied in-situ and in real-time the nucleation and co-growth dynamics of the peritectic structures in an Al-Mn alloy during solidification. We collected ∼30 TB 4D datasets which allow us to elucidate the phases’ co-growth dynamics and their spatial, crystallographic and compositional relationship. The primary Al4Mn hexagonal prisms nucleate and grow with high kinetic anisotropy -70 times faster in the axial direction than that in the radial direction. In all cases, a ∼5 µm Mn-rich diffusion layer forms at the liquid-solid interface, creating a sharp local solute gradient that governs subsequent phase transformation. The peritectic Al6Mn phases nucleate epitaxially within this diffusion zone, initially forming a thin shell surrounding the Al4Mn with an orientation relationship of {10
0}HCP // {110}O, [0001]HCP // [001]O. Such ∼5 µm Mn-rich diffusion layers also cause solute depletion at the liquid side of the liquid-solid interface, limiting further epitaxial phase growth, but prompting phase re-nucleation and branching at crystal edges, resulting tetragonal prism structures that no longer follow the initial orientation relationship. The anisotropic interfacial kinetics and local region latent heat release also led to the formation of liquid-filled core defects at the centre of both phases. Furthermore, increasing cooling rate from 0.17 to 20°C/s can disrupt the stability of the solute diffusion zone, effectively suppressing the formation of the core defects and forcing a transition from faceted to non-faceted morphologies. Our work provides systematic new knowledge and practical approach for tailoring and controlling the peritectic structures in metallic alloys through the solidification processes.
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May 2026
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[32893]
Abstract: Tetragonal tungsten bronzes (TTBs) have emerged as a promising structure type for Pb- and Bi-free ferroics for high–temperature stable multilayer ceramic capacitors. In this work, A- and B-site co-doped Sr2-2zNaCazYzNb5-zZrzO15 (with z = 0 to 0.075; SNN) ceramics exhibited a flattening of relative permittivity across a wide temperature range covering two dielectric anomalies: T2, a ferroelectric to paraelectric transition between 229 °C and 297 °C, and T1, a relaxor-ferroelectric peak between -8 °C and -70 °C. Rietveld refinement of synchrotron X-ray powder diffraction of the SNN ceramics using an orthorhombic Ama2 model, identified changes in the temperature evolution with doping of lattice parameters a, b and c, plus symmetry–driven distortion and strain modes including the ferroelectric polar mode distortion amplitude along c (
. A-site doping of smaller Ca2+ and Y3+ ions (for Sr2+), increases A-site disorder, working in combination with B-site doping of less polarisable Zr4+ ions (for Nb5+), disrupting long range commensurate ferroelectric ordering, via rigid unit-like octahedral tilting. This leads to an incommensurate modulation, whose associated strain is accommodated by an increasing stacking fault density, confirmed by TEM. This destabilises the ferroelectric polar mode (
onset temperature decreases, lowering T2), leading to increasing in orthorhombic strain in the ab plane (c axis compresses, inflection points of a and c at T1 diverge). Resulting in an increase in relaxor-like frequency dispersion of permittivity at T1 and a reduced negative thermal expansion of the c axis between T2 and T1, leading to a permittivity flattening.
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Apr 2026
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[33667]
Open Access
Abstract: The use of conventional zirconium alloys at temperatures above 400 °C is limited by high temperature strength and creep resistance. This has prevented the consideration of zirconium alloys for fusion and Generation IV fission plant designs operating at 500 °C–1000 °C. The physical metallurgy of zirconium is similar to titanium which has seen alloying advances allowing application temperatures up to 600 °C. Although the oxidation resistance of zirconium-based alloys is expected to be poor, in a water environment, new Generation-IV and fusion reactors are designed to operate using alternative coolants such as liquid metals and molten salts. Therefore, a new class of zirconium alloys in the Zr-Al-Sn-(Si,Cr,V) system, designed by analogy to near-
titanium alloys, were synthesised by arc melting and processed in a sequence of homogenisation, hot/cold rolling, recrystallisation, and ageing treatments. Microscopy and diffraction identified a refined fully lath grain structure reinforced by nanoscale lamellar or discrete coherent Zr3Al precipitates, with morphology and crystal structure differing with ageing times. Additionally alloying with Si, Cr, and V respectively leads to Zr2Si, ZrCr2, and ZrV2 incoherent precipitates. Tensile testing revealed a strengthening effect by Al, but with significant changes to ductility on ageing depending on the evolution of Zr3Al. Creep testing showed creep rates orders of magnitude better than conventional Zircaloy-4 and nuclear ferritic/martensitic steels, approaching near-
Ti alloys. The present work offers new insights and perspectives into how high-temperature zirconium alloys might be designed to meet the requirements for fusion and Gen-IV fission.
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Mar 2026
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[31134]
Open Access
Abstract: Growth kinetics and orientation selection play a significant role in microstructure evolution during metal solidification, while gravity-induced convection adds significant complexity to the process. In-situ, time-resolved X-ray imaging of solidifying grain-refined Al–20 wt.% Cu alloy onboard the MASER-13 sounding rocket enabled the study of equiaxed dendrite growth under diffusion-controlled conditions, eliminating the influence of gravity. A machine learning-enabled analytical pipeline was developed to extract and evaluate the spatiotemporal behaviour of a large number of individual dendrites, including their growth characteristics, rotations and interactions. Post-flight synchrotron X-ray computed tomography and electron backscatter diffraction were used to reconstruct the three-dimensional dendrite structure with embedded details of crystallographic orientations. Correlated data analysis confirmed that most dendrites grew along directions parallel to the {100} plane under highly isothermal, diffusion-controlled conditions. However, growth along atypical directions was also observed, even in this simplified regime. The benchmark data revealed variation in dendrite arm evolution, influenced by local grain interactions and crystallographic orientation selection. It is shown that the equiaxed grains have random crystallographic orientations and evidence suggests that these survive from shortly after nucleation in the bulk liquid under microgravity conditions. The data processing protocols demonstrated here highlight the potential of integrating advanced experimental techniques with modern data science approaches to analyse solidification microstructure formation in metallic alloys under terrestrial and microgravity conditions.
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Oct 2025
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[36212]
Abstract: Fe-rich intermetallic compounds (IMCs) are a persistent challenge in the recirculation of secondary aluminium alloys. Despite significant research effort, largely via post-solidification studies, the mechanisms governing IMC phase selection in higher-Fe (
wt.%), recycled Al alloys and how they can be controlled to facilitate more benign IMC species and/or morphologies remain poorly understood. This creates barriers to compositional and process design for more Fe-tolerant alloys. In this paper, we present a systematic real-time investigation of IMC formation, phase selection and morphological evolution in recycled 3xx series Al alloys with elevated Fe concentrations (up to 2.5 wt%), using in situ synchrotron X-ray radiography. Coupled with thermodynamic simulations, we develop a method to reliably estimate the formation temperatures of primary
-AlFeSi and
-AlFeSi IMCs, and show direct insights into their formation sequence and kinetics. Contrary to widely held assumptions based on low Fe-containing (
0.6 wt%) primary alloys, we show that in recycled alloys containing higher Fe concentrations, increased cooling rate significantly promotes the formation of the more anisotropic
-AlFeSi (over the more compact
-AlFeSi), which however can be fully suppressed at slow cooling. We propose how a solute-suppression mechanism kinetically controls the
/
IMC phase evolution. Further, we reveal and quantify a faceted-to-non-faceted morphological transition of
-AlFeSi from a faceted polyhedral to non-faceted near-equiaxed dendritic morphology. This transition is governed by an interplay between solidification velocity and liquid undercooling at the local IMC/liquid interfaces. This study provides insights into how solidification conditions may be leveraged to improve microstructural control in high Fe-containing recycled alloys.
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Oct 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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J. R.
Miller
,
H. C.
Cole
,
J. M.
Hogg
,
J.
Pitchforth
,
L. D.
Connor
,
P.
Vacek
,
S.
Neumeier
,
N. L.
Church
,
P. A.
Midgley
,
D. M.
Collins
,
C. M. F.
Rae
,
H. J.
Stone
Diamond Proposal Number(s):
[31966]
Open Access
Abstract: Single crystal Ni-base superalloys, like many materials containing an A1 structured phase, demonstrate additional forbidden reflections in diffraction experiments. These additional reflections are most commonly attributed to the presence of chemical short-range order, or to thin foil effects in transmission electron microscopy. In this study, transmission electron diffraction and synchrotron X-ray diffraction were used to interrogate the deformation mechanics in a single crystal Ni-base superalloy at room temperature. Additional reflections were observed around those from the A1 phase in both diffraction experiments, arising from relrods along . These relrods were linked to the formation of extensive intrinsic stacking faults (ISFs) within the A1 phase, giving rise to local disorder and a relaxation of the Bragg condition. This study represents the first use of single crystal X-ray diffraction to characterise forbidden reflections in A1 structures from bulk specimens, thereby discounting thin foil effects completely.
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Sep 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[31855]
Open Access
Abstract: Directed energy deposition (DED) laser additive manufacturing (AM) is a promising technique for building complex components and performing repair applications. However, large defects can form through coalescence of argon bubbles from the feedstock powder, potentially reducing end-component mechanical performance. Here, we used correlative high-speed synchrotron X-ray and infrared imaging, coupled with multiphysics modelling to develop a strategy to control defect formation. We demonstrate that the bubble dynamics can be controlled by appropriately modulating the laser power, temporarily disrupting the Marangoni flow, enabling bubble release. The bubble control mechanisms discovered here provide a way to achieve defect-lean AM.
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Sep 2025
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I11-High Resolution Powder Diffraction
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Kan
Ma
,
Pedro A.
Ferreiros
,
Thomas W.
Pfeifer
,
Robert G.
Abernethy
,
Sophia
Von Tiedemann
,
Nianhua
Peng
,
Graeme
Greaves
,
Colin
Ophus
,
Kai
Sun
,
Anamul H.
Mir
,
Lumin
Wang
,
Shasha
Huang
,
Shijun
Zhao
,
Patrick E.
Hopkins
,
Christopher D.
Hardie
,
Alexander J.
Knowles
Diamond Proposal Number(s):
[32708]
Open Access
Abstract: Intermetallic dispersion-strengthening (IDS) using nano-scale coherent intermetallic precipitates offers a potent strategy to produce high-strength and radiation-resistant steels, whilst addressing the manufacturability challenges of analogous oxide dispersion-strengthened (ODS) steels. However, their performance with intermetallic stability under irradiation damage, such as radiation-induced hardening (RIH), whilst hypothesised, is undemonstrated. Here, we report on a model IDS α(A2) + α’(L21) Fe-Ni-Al-Ti ferritic superalloy, which exhibits exceptional resistance to RIH with near-zero hardening after irradiation at 300°C 1 dpa, in contrast to significant RIH in a counterpart coarse precipitate alloy (increase in nano-hardness of 1.0 GPa) and Eurofer97 (0.7 GPa). This irradiation resistance is attributed to the high density of semi-coherent precipitate-matrix interfaces, and partial-disordering L21->B2 which causes a decrease in anti-phase boundary energy. High interface density with localised interfacial strain offers effective sinks, suppressing defect populations compared to the counterpart with lower interface density. Meanwhile, atomic resolution spectroscopy and irradiation with in-situ transmission electron microscopy show that the disordering stems from Al-rich and Ti-rich sublattices mixing in the initial L21-Ni2AlTi structure below 500°C, forming metastable B2-Ni(Al,Ti). Combined, the high interface density and radiation-induced intermetallic disordering underpin the remarkable radiation tolerance, demonstrating the IDS concept as a promising radiation-resistant materials design strategy.
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May 2025
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