I11-High Resolution Powder Diffraction
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Open Access
Abstract: The first reported phase in the Y2O3–NiO–TiO2 chemical space, the Y2NiTiO6 perovskite undergoes a temperature-induced order–disorder transition. Above ∼1700 K, it adopts the structure of a disordered CaTiO3-type orthorhombic perovskite with a = 5.26939(2), b = 5.60367(2), and c = 7.58137(3) Å, with the B site uniformly occupied by 0.5Ni+0.5Ti. Below this temperature, Y2NiTiO6 adopts rock-salt ordering of the transition metals in a monoclinic unit cell (a = 5.26695(2), b = 5.60164(2), c = 7.57493(2) Å, β = 90.4940(2)°) with 0.9/0.1 ordering of the B site. Ordering of Ni and Ti changes the magnetic properties from spin-glass behavior in the orthorhombic phase to antiferromagnetic order (TN = 17 K) for the monoclinic phase, while the optical properties of both phases remain unchanged across the transition.
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Oct 2025
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[34632, 31578]
Open Access
Abstract: Biomass conversion involves transforming sustainable feedstocks into valuable intermediates for the chemical industry. A key biomass-derived platform molecule, 5-hydroxymethylfurfural (HMF), can be converted into various intermediates, including 2,5-diformylfuran (DFF), which has several industrial applications due to its versatile chemical reactivity. Herein, Cu loaded MOF-808, with three different Cu loadings, were synthesised and tested as catalysts for the liquid phase selective oxidation of HMF to DFF with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) were performed to assess the speciation of Cu, with the development of a structure model of MOF-808(Cu3). The structural analysis reveals that single square planar Cu(II) sites are located near the Zr6 cluster and are bonded by coordinating to oxygen atoms of capping MeOH and H2O ligands. Amongst the synthesised catalysts, MOF-808(Cu3) exhibited the highest catalytic activity after 12 h, achieving a high HMF conversion (95.5 ± 2.7%) and DFF yield (78.9 ± 1.3%) at 30 °C. The nature of the catalytic reaction is heterogeneous as the yield of DFF decreases after the removal of the solid catalyst. The demonstration of catalytic activity with high selectivity under near ambient conditions advances the application of porous metal–organic framework-based catalysts for selective liquid phase oxidations.
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Oct 2025
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I11-High Resolution Powder Diffraction
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Open Access
Abstract: The ordering of multiple organic linkers with different sizes and geometries on metal–organic frameworks (MOFs) offers structures with advanced complexity and functionality for enhanced properties. The selection of the components and the number of synthesis steps are commonly rationalized to match existing structural motifs in order to increase the probability of producing the designed new frameworks. Alternatively, combining multiple components, without a preconceived structural model, allows for the exploration of unprecedented structural characteristics. However, this approach requires a large number of experiments to identify both the composition and conditions for a successful synthesis. Here, we report a new Zr-MOF containing ordered straight and bent dicarboxylate linkers prepared by a one-pot synthesis. The discovery was made by high-throughput exploration of the chemical space composed of two linkers, the source of Zr, and the modulator. The linkers and the Zr6 cluster are ordered on an fcu framework that is tetragonally distorted from its typical cubic symmetry. The arrangement of linkers with different sizes and geometries affords cages and windows with shapes that have not been reported previously, despite the plethora of known fcu-based MOFs. The new MOF exhibits chromatographic separation of the n-hexane/benzene/cyclohexane mixture and demonstrates reversible unbinding and rebinding of the bent linkers upon the addition and removal of protic solvents. The unusual structural properties of the new MOF arise from ordering linkers in a non-predetermined manner following high-throughput synthesis exploration.
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Jul 2025
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I11-High Resolution Powder Diffraction
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Jungwoo
Lim
,
Manel
Sonni
,
Luke M.
Daniels
,
Mounib
Bahri
,
Marco
Zanella
,
Ruiyong
Chen
,
Zhao
Li
,
Alex R.
Neale
,
Hongjun
Niu
,
Nigel D.
Browning
,
Matthew S.
Dyer
,
John B.
Claridge
,
Laurence J.
Hardwick
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578]
Open Access
Abstract: LiNiO2 positive electrode materials for lithium-ion batteries have experienced a revival of interest due to increasing technological energy demands. Herein a specific Ti4+ substitution is targeted into LiNiO2 to access new compositions by synthesizing the LiNi1–xTi3x/4O2 solid solution with the aim of retaining Ni3+. Compositions in the range 0.025 ≤ x ≤ 0.2 form nanocomposites of compositionally homogeneous ordered R
m and disordered Fm
m rock salt domains as observed via X-ray and neutron diffraction, and STEM. The disordered rock salt domains stabilize the ordered structure to provide excellent structural reversibility via the formation of coherent interfaces during cycling and enable deep delithiation using a constant voltage charging step without structural degradation. The detrimental structural phase transitions associated with the poor cyclability of LiNiO2 are suppressed to yield a low strain positive electrode material with high capacity retention that offers high-rate capability even under increased cell electrode mass loadings. The composition x = 0.075 (LiNi0.925Ti0.05625O2) affords a 93% capacity retention after 100 cycles (100 mA g−1) and demonstrates high reversible capacities of 125 mAh g−1 even under rates of 3200 mA g−1. LiNi0.925Ti0.05625O2 exhibits exceptional performance at electrode mass loadings (13.6 mg cm−2) comparable to those required for commercial cell applications.
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Jul 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[23666]
Open Access
Abstract: Perovskites offer vast flexibility in tuning subtle distortions in their structures through their innate ability to host a wide range of compositional combinations. Minor changes in composition can dramatically influence the properties observed through structural distortions such as octahedral tilting. In addition to understanding their properties, in magnetic materials, the magnetic structure is also tied to the nuclear structural distortions and can have more complex behavior with changing composition. In this work we report on the magnetic properties, and nuclear and magnetic structures of the solid solution (1 – x)BiFeO3 – (x/2)Ca2Fe4/3W2/3O6. With the exception of BiFeO3, all samples show a weak ferromagnetic behavior arising from spin canting. We find that despite only one structural phase transition occurring from R3c to Pnma in this solid solution, the magnetic phase diagram is far more complex, with four distinct magnetic phases occurring in the compositional range 0.1 < x < 1. Using a combination of neutron and X-ray diffraction, we find that a crossover between long and short Fe–O bond lengths and divergence of Fe–O–Fe bond angles with composition drive the changes in magnetic structure and can be correlated to the resulting magnetic properties.
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Jul 2025
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B18-Core EXAFS
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Diamond Proposal Number(s):
[31218]
Open Access
Abstract: Several classes of inorganic transparent conducting coatings are available (broad band wide band gap semiconductors, noble metals, amorphous oxides and correlated metals), with peak performance depending on the layer thickness. Correlated metallic transition metal oxides have emerged as potential competitive materials for small coating thicknesses, but their peak performance remains one order of magnitude below other best in class materials. By exploiting the charge transfer at the interface between a correlated metal (SrNbO3) and a wide band gap semiconductor (SrTiO3), we show that pulsed laser deposition-grown SrNbO3 heterostructures on SrTiO3 outperform correlated metals by an order of magnitude. The apparent increase in carrier concentration confirms that an electronically active interfacial layer is contributing to the transport properties of the heterostructure. The correlated metallic electrode allows the extraction of high mobility carriers resulting in an enhanced conductivity for heterostructures with thicknesses up to 20 nm. The high optical absorption of the high mobility metallic interface does not have a detrimental effect on the transmission of the heterostructure due to its small thickness. The charge transfer-driven enhanced electrical properties in correlated metal - wide band gap semiconductor heterostructures offer a distinct route to high performance transparent conducting materials.
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May 2025
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I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[36629, 31578]
Open Access
Abstract: Apatites are an important mineral-based material family with huge chemical and structural diversity. They were recently implicated in the claims of high-temperature superconductivity in materials labeled LK-99 that display complex phase mixtures containing Pb, Cu, phosphate, and oxide components. We report Cu-substituted lead apatite solid solutions Pb10–xCux(PO4)6O that display two distinct compositional ranges differentiated by structural ordering. For x > 0.5, we observe substitution in the apatite archetype structure, whereas for x < 0.5, we find an apatite superstructure with coupled anion and cation ordering. The 1 × 1 × 2 superstructure in the noncentrosymmetric space group P6̅ (no. 174) for Pb10–xCux(PO4)6O with x < 0.5 exhibits a unique oxygen ordering motif in the hexagonal channels and selective Cu substitution only on two out of seven Pb sites. At x > 0.5 in Pb10–xCux(PO4)6O, Cu cations are introduced onto all Pb sites, which triggers the transition to the archetypical apatite structure, reflecting the coupling of the core structural components of the apatite framework in the ordering pattern.
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Apr 2025
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I11-High Resolution Powder Diffraction
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Matthew J.
Rosseinsky
,
Moinak
Dutta
,
Angelos B.
Canaj
,
Tilen
Knaflič
,
Christopher M.
Collins
,
Troy D.
Manning
,
Hongjun
Niu
,
Luke M.
Daniels
,
Aikaterini
Vriza
,
Luke A.
Johnson
,
Bhupendra
Mali
,
Yuri
Tanuma
,
Todd Wesley
Surta
,
John B.
Claridge
,
Neil
Berry
,
Denis
Arčon
,
Matthew S.
Dyer
Open Access
Abstract: We report the synthesis, structural characterization and magnetic properties of K3coronene, and demonstrate a computational screening workflow designed to accelerate the discovery of metal intercalated polycyclic aromatic hydrocarbon (PAH), a class of materials of interest following reports of superconductivity, but lacking demonstrated and understood characterised materials compositions. Coronene is identified as a suitable PAH candidate from a library of PAHs for potassium intercalation by computational screening of their electronic structure and of the void space in their crystal structures, targeting LUMO similarity to C60 and the availability of suitable sites to accommodate inserted cations. Convex hull calculations with energies from crystal structure prediction based on ion insertion into the identified void space of coronene suggest that the x = 3 composition in Kxcoronene is stable at 0 K, reinforcing the suitability of coronone for experimental investigation. Exploration of reaction conditions and compositions revealed that the mild reducing agent KH allows formation of K3coronene. The structure of K3coronene solved from synchrotron powder X-ray diffraction features extensive reorientation and associated disorder of coronene molecules compared with the parent pristine host. This is driven by K+ intercalation and occupation of sites both within and between the coronene stacks that are partially retained from the parent structure. This disruption of the host structure is greater when three cations are inserted per coronene than in reported metal PAH structures where the maximum ratio of cations to PAH is 2. Superconductivity is not observed, contrary to previous reports on Kxcoronene. The expected localised moment response of coronene3- is suppressed, which may be associated with the combination of extensive disorder and close coronene3- - coronene3- contacts.
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Dec 2024
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[29271, 31578]
Open Access
Abstract: The catalytic hydrogenolysis process offers the selective production of high-value liquid alkanes from waste polymers. Herein, through normalisation of Ni structure, Ni mass and density, and CeO2 crystallite size, the importance of CeO2 nanocube morphology in the hydrogenolysis of polypropylene (Mw = 12[thin space (1/6-em)]000 g mol−1; Mn = 5000 g mol−1) over Ni/CeO2 catalysts was determined. High liquid productivities (65.9–70.9 gliquid gNi−1 h−1) and low methane yields (10%) were achieved over two different Ni/CeO2 catalysts after 16 h reaction due to the high activity and internal scission selectivity of the supported ultrafine Ni particles (<1.3 nm). However, the Ni/CeO2 nanocube catalyst exhibited higher C–C scission rates (838.1 mmol gNi−1 h−1) than a standard benchmark mixed shape Ni/CeO2 catalyst (480.3 mmol gNi−1 h−1) and represents a 75% increase in depolymerisation activity. This led to shorter hydrocarbon chains achieved by the nanocube catalyst (Mw = 2786 g mol−1; Mn = 1442 g mol−1) when compared to the mixed shape catalyst (Mw = 4599 g mol−1; Mn = 2530 g mol−1). The enhanced C–C scission rate of the nanocube catalyst was determined to arise from a combination of improved H-storage and favourable basic properties, with higher weak basic site density key to facilitate a greater degree of hydrocarbon chain adsorption.
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Dec 2024
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Matthew A.
Wright
,
Jungwoo
Lim
,
Raul A.
Pacheco Muino
,
Anna E.
Krowitz
,
Cara J.
Hawkins
,
Mounib
Bahri
,
Luke M.
Daniels
,
Ruiyong
Chen
,
Luciana
Gomes Chagas
,
James
Cookson
,
Paul
Collier
,
Alan V.
Chadwick
,
Nigel D.
Browning
,
John B.
Claridge
,
Laurence J.
Hardwick
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578]
Open Access
Abstract: V2Se9 displays facile electrochemical insertion of up to 1.6 Mg2+ per unit formula with fast diffusion (coefficients of 10-10 – 10-12 cm2 s-1) surpassing best-in-class materials like Mo6S8. Detailed structural characterization of synchrotron X-ray diffraction data with ab initio Maximum Entropy Method analysis reveals Mg2+ insertion onto octahedral sites within the large vdW space between [V4Se18]∞ chains. Fast rate performance is attributed to low structural perturbation and low diffusion barriers, calculated by bond valence pathway analysis, resulting from the low charge-per-size of anionic selenium. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy reveal that reversible insertion of Mg2+ is facilitated by V5+/V3+ redox. V2Se9 demonstrates that selenides, despite their larger molecular weight, offer potential as fast rate positive electrode materials for magnesium batteries over well-explored oxides and sulfides.
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Oct 2024
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