B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[25407]
Abstract: Mechanofluorochromic materials are of great significance for the fabrication of innovative sensors and optoelectronics. However, efficient mechanofluorochromic materials are rarely explored due to the deficiency of existing design strategies. Here, we demonstrate the incarceration of aggregation-induced emission (AIE) materials within metal-organic framework (MOF) single crystals to construct a composite system with turn-on mechanofluorochromism. A new type of AIE@MOF material was designed: integrating a zeolitic MOF (ZIF-71) and tetraphenylethylene (TPE, a topical AIE material) to generate a TPE@ZIF-71 system with exceptional turn-on type mechanofluorochromism. Using terahertz vibrational spectroscopy, we show the unique fluorochromism mainly emanates from the enhanced nanoconfinement effect exerted by ZIF-71 host on TPE guest under pressure. Compared with pure TPE, we demonstrate the nanoconfinement in AIE@MOF not only changes the TPE's turn-off type sensing behavior to a turn-on type, but boosts the original sensitivity markedly by tenfold. Significantly, because ZIF-71 prevents the spontaneous recrystallization of TPE upon unloading, this allows TPE@ZIF-71 to record the stress history. This is the first demonstration of the Guest@MOF system combining the concepts of AIE and MOF; its promising properties and potential engineering applications will stimulate new directions pertaining to luminescent stress sensors and smart optics.
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Jun 2022
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I11-High Resolution Powder Diffraction
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A. J. R.
Thom
,
D. G.
Madden
,
R.
Bueno-Perez
,
A.n.
Al Shakhs
,
C. T.
Lennon
,
R. J.
Marshall
,
C. A.
Walshe
,
C.
Wilson
,
C. A.
Murray
,
S. P.
Thompson
,
G. F.
Turner
,
D.
Bara
,
S. A.
Moggach
,
D.
Fairen-Jimenez
,
R. S.
Forgan
Diamond Proposal Number(s):
[22028]
Open Access
Abstract: To achieve optimal performance in gas storage and delivery applications, metal–organic frameworks (MOFs) must combine high gravimetric and volumetric capacities. One potential route to balancing high pore volume with suitable crystal density is interpenetration, where identical nets sit within the void space of one another. Herein, we report an interpenetrated MIL-53 topology MOF, named GUF-1, where one-dimensional Sc(μ2-OH) chains are connected by 4,4′-(ethyne-1,2-diyl)dibenzoate linkers into a material that is an unusual example of an interpenetrated MOF with a rod-like secondary building unit. A combination of modulated self-assembly and grand canonical Monte Carlo simulations are used to optimise the porosity of GUF-1; H2 adsorption isotherms reveal a moderately high Qst for H2 of 7.6 kJ/mol and a working capacity of 41 g/L in a temperature–pressure swing system, which is comparable to benchmark MOFs. These results show that interpenetration is a potentially viable route to high-performance gas storage materials comprised of relatively simple building blocks.
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Jun 2022
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[20876]
Abstract: A new metastable phase in flash-frozen disordered Prussian blue analogues is reported. The phase is characterised by the appearance of diffuse scattering clouds and the reduction of the local structure symmetry: from cubic to a tetragonal or lower space group. The phase transition is characterised by the translational modulation of the structure and is likely caused by the freezing of the water confined in the pores of the structure.
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Jun 2022
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B22-Multimode InfraRed imaging And Microspectroscopy
Optics
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Diamond Proposal Number(s):
[413]
Abstract: Focal plane array (FPA) detectors have escalated Fourier transform infrared (FTIR) microspectroscopy to a potent hyperspectral imaging method. Yet, despite the instrumental multiplex/multichannel advantages, the fidelity of the hyperspectral images relies on the throughput as the total flux of the source is divided among each FPA pixel. Additionally, maintaining the spectral resolution requires a certain level of collimation of the beam which adversely affect the flux of high étendue source. To this end, we propose an implementation of two deformable mirror (DM) sensorless adaptive optics system for infrared (IR) source coupling. The deflection shape of each DM membrane is optimized individually to deal with the beam intensity and the rays’ direction in a separate manner, while preserving the spectral quality across the entire mid-IR range. This paper contemplates the choice of metrics in sequential optimization in conjunction with two variations of stochastic parallel gradient descent optimization algorithm. We discuss this approach with respect to a state-of-the-art FTIR microscope.
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Jun 2022
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[17433]
Abstract: Fast Li-ion conductivity at room temperature is a major challenge for utilization of all-solid-state Li batteries. Metal borohydrides with neutral ligands are a new emerging class of solid-state ionic conductors, and here we report the discovery of a new mono-methylamine lithium borohydride with very fast Li + conductivity at room temperature. LiBH 4 ∙CH 3 NH 2 crystallizes in the monoclinic space group P 2 1 / c , forming a two-dimensional unique layered structure. The layers are separated by hydrophobic –CH 3 moieties, and contain large voids, allowing for fast Li-ionic conduction in the interlayers, σ(Li+) = 1.24∙10 -3 S/cm at room temperature. The electronic conductivity is negligible, and the electrochemical stability is ~2.1 V vs Li. The first all-solid-state battery using a lithium borohydride with a neutral ligand as the electrolyte, Li-metal as the anode and TiS 2 as the cathode is demonstrated.
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Jun 2022
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I12-JEEP: Joint Engineering, Environmental and Processing
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Fabio
Arzilli
,
Margherita
Polacci
,
Giuseppe
La Spina
,
Nolwenn
Le Gall
,
Edward W.
Llewellin
,
Richard A.
Brooker
,
Rafael
Torres-Orozco
,
Danilo
Di Genova
,
David A.
Neave
,
Margaret E.
Hartley
,
Heidy M.
Mader
,
Daniele
Giordano
,
Robert
Atwood
,
Peter D.
Lee
,
Florian
Heidelbach
,
Mike R.
Burton
Diamond Proposal Number(s):
[16188]
Open Access
Abstract: The majority of basaltic magmas stall in the Earth’s crust as a result of the rheological evolution caused by crystallization during transport. However, the relationships between crystallinity, rheology and eruptibility remain uncertain because it is difficult to observe dynamic magma crystallization in real time. Here, we present in-situ 4D data for crystal growth kinetics and the textural evolution of pyroxene during crystallization of trachybasaltic magmas in high-temperature experiments under water-saturated conditions at crustal pressures. We observe dendritic growth of pyroxene on initially euhedral cores, and a surprisingly rapid increase in crystal fraction and aspect ratio at undercooling ≥30 °C. Rapid dendritic crystallization favours a rheological transition from Newtonian to non-Newtonian behaviour within minutes. We use a numerical model to quantify the impact of rapid dendritic crystallization on basaltic dike propagation, and demonstrate its dramatic effect on magma mobility and eruptibility. Our results provide insights into the processes that control whether intrusions lead to eruption or not.
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Jun 2022
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[28680]
Open Access
Abstract: SrTiO3 (STO) is an incipient ferroelectric perovskite oxide for which the onset of ferroelectric order is suppressed by quantum fluctuations. This property results in a very large increase in static dielectric constant from ∼300 at room temperature to ∼20,000 at liquid He temperature in bulk single crystals. However, the low-temperature dielectric constant of epitaxial STO films is typically a few hundred to a few thousand. Here, we use all-epitaxial capacitors of the form n-STO/undoped STO/n-STO (001) prepared by hybrid molecular beam epitaxy, to demonstrate intrinsic dielectric constants of an unstrained STO (001) film exceeding 25,000. We show that the n-STO/undoped STO interface plays a critically important role not previously considered in determining the dielectric properties that must be properly accounted for to determine the intrinsic dielectric constant.
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Jun 2022
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[14692]
Open Access
Abstract: Marine cyanobacteria are critical players in global nutrient cycles that crucially depend on trace metals in metalloenzymes, including zinc for CO2 fixation and phosphorus acquisition. How strains proliferating in the vast oligotrophic ocean gyres thrive at ultra-low zinc concentrations is currently unknown. Using Synechococcus sp. WH8102 as a model we show that its zinc-sensor protein Zur differs from all other known bacterial Zur proteins in overall structure and the location of its sensory zinc site. Uniquely, Synechococcus Zur activates metallothionein gene expression, which supports cellular zinc quotas spanning two orders of magnitude. Thus, a single zinc sensor facilitates growth across pico- to micromolar zinc concentrations with the bonus of banking this precious resource. The resultant ability to grow well at both ultra-low and excess zinc, together with overall lower zinc requirements, likely contribute to the broad ecological distribution of Synechococcus across the global oceans.
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Jun 2022
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Krios I-Titan Krios I at Diamond
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Diamond Proposal Number(s):
[21643]
Open Access
Abstract: Mitoribosomes are essential for the synthesis and maintenance of bioenergetic proteins. Here we use cryo-electron microscopy to determine a series of the small mitoribosomal subunit (SSU) intermediates in complex with auxiliary factors, revealing a sequential assembly mechanism. The methyltransferase TFB1M binds to partially unfolded rRNA h45 that is promoted by RBFA, while the mRNA channel is blocked. This enables binding of METTL15 that promotes further rRNA maturation and a large conformational change of RBFA. The new conformation allows initiation factor mtIF3 to already occupy the subunit interface during the assembly. Finally, the mitochondria-specific ribosomal protein mS37 (ref. 1) outcompetes RBFA to complete the assembly with the SSU–mS37–mtIF3 complex2 that proceeds towards mtIF2 binding and translation initiation. Our results explain how the action of step-specific factors modulate the dynamic assembly of the SSU, and adaptation of a unique protein, mS37, links the assembly to initiation to establish the catalytic human mitoribosome.
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Jun 2022
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I21-Resonant Inelastic X-ray Scattering (RIXS)
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Diamond Proposal Number(s):
[21725]
Open Access
Abstract: Cuprate superconductors have the highest critical temperatures (Tc) at ambient pressure, yet a consensus on the superconducting mechanism remains to be established. Finding an empirical parameter that limits the highest reachable Tc can provide crucial insight into this outstanding problem. Here, in the first two Ruddlesden-Popper members of the model Hg-family of cuprates, which are chemically nearly identical and have the highest Tc among all cuprate families, we use inelastic photon scattering to reveal that the energy of magnetic fluctuations may play such a role. In particular, we observe the single-paramagnon spectra to be nearly identical between the two compounds, apart from an energy scale difference of ~30% which matches their difference in Tc. The empirical correlation between paramagnon energy and maximal Tc is further found to extend to other cuprate families with relatively high Tc’s, hinting at a fundamental connection between them.
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Jun 2022
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