cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1820236
title: Linking the solid state and solution thorium aqua structures: A solid state powder neutron diffraction investigation

description: A understanding of the aqueous chemistry of the actinide ions is not as well developed as for transition metals or the lanthanides. Fundamentally important information such as the number of coordinated water molecules is still under debate. This has relied on EXAFS, but this technique cannot give precise coordination numbers. In this work we aim, for the first time, to use neutron diffraction techniques to explicitly locate the coordinated water molecules in three thorium compounds (with bromide, sulfate and chloride ions) of increasing complexity, and understand how these interact with the second coordination shell. In a related submission, we will examine the solution phase structures to gain further information on the structures and stability of these. This information is vital for the storage of spent nuclear fuel either in a geological repository or solution phase processing.
DOI: 10.5286/isis.e.rb1820307
title: Unidentified Phase Transition in Polar Lanthanum Tantalate (LaTaO4)

description: The family of crystals with formula ABX4 represent a very interesting class of ferroelectrics that are extremely two-dimensional. Fluorides have been extensively researched but there is great potential for oxides of this class, such as LaTaO4, due to oxides being favoured for device applications. Studies have reported the evolution of morphologies of LaTaO4 with temperature, but one phase transition at ~200ºC is accompanied by an anomalously small peak in permittivity, which suggests the transition is unusual. Variable temperature XRD of this material has revealed a change in lattice parameters which coincide with the phase transition but this is suspected to be a consequence of a shift in oxygen positions. It is then suggested that by using HRPD, the change in oxygen positions can be observed across the phase transition and hence the structural distortion can be characterised.
DOI: 10.5286/isis.e.rb1820312
title: Magnetic structure of the frustrated mixed-valence iridate Ba3LaIr2O9

description: Mixed-valence iridates are the new platform for studying frustrated magnets and achieving exotic quantum spin liquid ground states. Magnetic interactions in such systems remain largely unknown and obscured by the combination of several competing energy scales that render the microscopic description highly challenging. By resolving the magnetic structure of Ba3LaIr2O9, we envisage to obtain experimental insight into magnetic interactions and gain the knowledge that can be extended to sibling iridates, including Ba3InIr2O9, where signatures of the spin-liquid behavior have been observed.
DOI: 10.5286/isis.e.rb1900030
title: Time of Flight MIEZE

description: We wish to construct a spectrometer on the Larmor instrument capable of resolving very small energy transfers between the neutron and the sample. To achieve this we will use a method called MIEZE. This technique encodes the energy transfer in the neutron spin by using two radio frequency (RF) spin flippers. The first RF flipper will cause the beam polarisation to rotate in a certain direction. The second RF flipper will cause the polarisation to rotate in the opposite direction. The detector is placed at the position were the number of rotations induced by the second flipper is equal to the number of rotations induced by the first flipper.When a sample is placed in the beam which changes the energy of the neutrons, the detector will see a decrease in polarisation. As a result the change in polarisation is a measure for the energy transfer between the sample and the neutrons.
DOI: 10.5517/ccdc.csd.cc21zppf
title: CCDC 1906335: Experimental Crystal Structure Determination

description: Related Article: F. Thoelen, W. Frank|2019|Acta Crystallogr.,Sect.E:Cryst.Commun.|75|557|doi:10.1107/S2056989019004201
description: An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
DOI: 10.5517/ccdc.csd.cc2211bj
title: CCDC 1907626: Experimental Crystal Structure Determination

description: Related Article: Brian W. Skelton, Murray V. Baker, Peter J. Barnard|2019|CSD Communication|||
description: An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
DOI: 10.5286/isis.e.rb1720041
title: Investigation of nuclear and magnetic structures of new modifications of BaCoO3-x, and topochemically modified oxyfluorides

description: Barium cobaltites are interesting materials because of a broad range of properties (magnetic, catalytic, electronic). Such properties are tightly connected to the structure type (so called hexagonal vs. cubic perovskite compounds) and compositions of the compounds. By the latter, different oxidation states of the cobalt ions can be assessed, which give rise to the various properties. In our recent research we found three new modifications of barium cobaltitets which have been so far unknown in this system. Additionally, those compounds can be modified by means of topochemical fluorination reactions. Within this proposal we aim to investigate nuclear (ordering of anion vacancies and structural distortions) and magnetic structures of such compounds, and the influence of composition and vacancy order on the spin states and magnetic properties of the cobalt ions.
DOI: 10.5286/isis.e.rb1770017
title: Probing Spin Dynamics in the Tomonaga-Luttinger Liquid (TLL) State by means of µSR study in the CsO2

description: The TLL phase is a quantum spin condensed state in the one-dimensional system. In the case of DIMPY system which is a quasi-one-dimensional organic magnet, the TLL phase is induced by the magnetic field forming a sea of the singlet spin state with some excited triplet spins. The µSR measurement successfully picks up the spin-relaxation behavior in the TLL phase in this system. Our target system to study the TLL state is the CsO2 which is one of superoxides series which we are currently working to investigate magnetic properties of magnetic moment on the O2 dumbbell. It is recently reported from NMR measurement that the TLL phase is realized in this system also below about 30 K down to TN~9 K. Since the µSR study in the DIMPY system is well working on the TLL phase, we follow the similar measurement on CsO2.  We try to achieve more accurate information on the TLL phase rather than NMR.
DOI: 10.5286/isis.e.rb1800088
title: VALIDATE HARDENING SOLUTIONS FOR OBJECT-DETECTION ALGORITHMS FOR AUTOMOTIVE APPLICATIONS

description: The goal of this proposal is to continue our evaluation of the resilience of modern parallel devices for automotive applications. We will study the neutron sensitivity of modern System on Chips embedding ARM core (with the BIG-little technology), FPGA programmable logic, Graphics Processing Units, and multi-core processors. During our experiments we will run object-detection frameworks for automotive applications implementing the hardening solutions we have developed based on previous experiments results.
DOI: 10.5286/isis.e.rb1810087
title: Mixed H/F-Carbon surfactant monolayers for fire-fighting applications

description: The aim is to use Neutron Reflectivity (NR) to gain essential information on the adsorption properties of fluorocarbon/ hydrocarbon mixtures in commercial fire-fighting foam formulations.  These practical surfactants (Figure 1) have already been studied individually by NR, and a good understanding of their interfacial properties has been gained. Therefore, these results will be able to provide essential information on which surfactants are dominating the interfacial properties of the fire-fighting foam formulation. This is the second stage in a new 3-year program, including NR, so that F-carbon surfactants can be replaced by more environmentally-responsive low-F or hydrocarbon analogues.  Chris Hill is a 3rd year PhD student fully funded by fire-fighting technology company Angus Fire.
DOI: 10.5286/isis.e.rb1810266
title: Kohn anomaly in a triangular-lattice quantum-spin-liquid candidate

description: A quantum spin liquid (QSL) shows no magnetic order down to zero temperature but the spins are highly entangled. In a 2D spin-1/2 triangular-lattice QSL YbMgGaO4, our previous neutron scattering measurements have revealed dispersive spinon excitations with a clear upper excitation edge. Here, we propose to study its phonon excitations in details to look for Kohn anomaly in spin channel. The Kohn anomaly behaves as a deviation of phonon excitations from its conventional dispersion at the nesting vector of spinon Fermi surface. It will be enhanced with decreasing temperature due to the development of QSL state. The observation of Kohn anomaly can not only provide unambiguou evidence of spinon Fermi surfaces, but also make it possible to evaluate the topology of the spinon Fermi surface from the wave vector.
DOI: 10.5286/isis.e.rb1810459
title: Structural refinement of new class of thermo-responsive nanogels to optimise their interfacial behaviour

description: Understanding the transport and adsorption dynamics of nanogels at interfaces as a function of structural morphology are of great importance to further their development and potential applications. NMR experiments have shown that the structures of these nanogels can be manipulated and tuned through synthetic steps. The aim of this experiment is to relate the adsorption behaviour to structural morphology (i.e. synthetic steps).
DOI: 10.5286/isis.e.rb1810565
title: Inelastic Neutron Scattering Studies of C-H Bond Activation in Organo-rhodium Anticancer Complexes

description: Cp* ligands are usually considered to be innocent in metallodrugs. However, we observed rapid sequential deuteration of all 15 Cp* methyl protons in RhIII complexes [(η5-Cp*)Rh(N,N)Cl]PF6 (Fig. 1), where Cp* is  pentamethylcyclopentadienyl anion and N,N = bipyridyl in aqueous media at ambient temperature. We have discovered that this sequential deuteration proceeds via a substituted fulvene intermediate. This unusual reactivity might contribute towards the anticancer activity of the complexes.  We aim to correlate of this unusual reactivity with the cancer cell cytotoxicity.  This proposed study will investigate the dynamics of the sequential deuteration using neutron scattering (on TOSCA) to elucidate the distribution of the incorporated deuterium within the Cp* ring at various levels of deuteration.
DOI: 10.5286/isis.e.rb1810566
title: PDF study of the effect of synthesis conditions on the local structure of hard carbons

description: Hard carbons are amongst the most promising anode materials for sodium-ion batteries, but their charge storage mechanisms are still poorly understood. Difficulties in characterizing their structures have led to a lack of detailed structure-property relationships. Their lack of long-range correlations, along with the formation of otherwise disordered, metastable, phases upon discharge hinders structural characterization. Here, we propose to study the formation of hard carbons resulting from different synthesis conditions using pair distribution function analysis to gain information about how the synthesis conditions affect the structure of the resultant carbon. This will be combined with electrochemical, Raman and solid-state NMR measurements in order to better understand the relationship between the carbon structure, its synthesis conditions and its behavior within a battery.
DOI: 10.5286/isis.e.rb1810574
title: Investigation of PVC plasticizers on phospholipid monolayers

description: Plastic bags are used as containers for storage of donated blood.  These bags are typically made out of PVC plasticized with dialkylphthalates (e.g. DEHP), which migrates into the blood and has been found to stabilize the membranes of red blood cells and thereby increases the shelf life of the stored blood.  DEHP is inherently toxic and a non-toxic alternative is desired that does not sacrifice shelf life of stored blood.  Using neutron reflectometry we aim to establish how different plasticizers interact with phospholipid monolayers and thereby connect biological functions to chemical effects.  Insight into the stabilization will lead to greater understanding of how to stabilize blood cells and increase the storage time of collected blood..
DOI: 10.5286/isis.e.rb1810699
title: Spinon Confinement and Longitudinal Interchain modes in Yb2Pt2Pb

description: The f-electron metal Yb2Pt2Pb is best thought of as a one dimensional (1D) quantum spin chain system, despite the fact that the magnetic moments are large and anisotropic with large orbital angular momentum.  We have previously shown using OSIRIS that in a magnetic field, the low energy magnetic excitations - quasiparticles called spinons - become confined in low energy bound states and gain coherence between the 1D chains in the magnetically ordered state.  There phenomena are condensed matter physics analogues to the quantum chromodynamics that governs the behavior of quarks and the Higgs boson, respectively.  We propose to study the development of these phenomena in the vicinity of the phase transition that signals their onset at modest applied magnetic fields of around 0.5 T.
DOI: 10.5286/isis.e.rb1810706
title: Self-assembly of low surface energy single chain surfactants at low and high salinity conditions

description: The research topic is Green Low Surface Energy Materials (LSEMs), with the aim to develop new hydrocarbon (HC) architectures to replace environmentally hazardous fluorocarbon surfactants for Enhanced Oil Recovery (EOR) applications. The aim is to explore how mono and divalent cations (in ambient and reservoir conditions) affect the structural behavior of surfactants in aqueous solutions. The surfactants of interest are shown in Figure 1: the subtle structural modifications in the head and tail, feed through to significant effects on surface tension and critical micelle concentration. Analyses of tensiometric data (Table 1) indicate that the higher the salinity of the surfactants solution, the lower the CMC and surface tension. This project is supported by a Sêr Cymru II Welsh Fellowship part-funded by the European Regional Development Fund (ERDF), Project Number: 80761-SU-021.
DOI: 10.5286/isis.e.rb1810755
title: Crystal electric field (CEF) effects in heavy fermion system YbRh3Si7

description: We studied a new metamagnetic heavy-fermion (HF) compound YbRh3 Si7, synthesized for the first time. This is the first HF compound in the ScRh3Si7 family, for which the only known rare earth-based compounds are non-magnetic REAu3Al7 (RE = Ce-Lu, except for Eu) , magnetic Eu(Rh,Ir)3 Ge7 , and YbAu3 Ga7 with unknown physical properties. In the 1-3-7 family, YbRh3Si7 is the first Kondo-lattice compound with antiferromagnetic (AFM) order below TN = 7.5 K. Multiple metamagnetic transitions (MMTs) are observed in field-dependent thermodynamic and electrical transport properties, giving rise to a dome like field-temperature phase diagram in YbRh3Si7. We proposed to study the CEF effects in this compound with inelastic neutron scattering.
DOI: 10.5286/isis.e.rb1820613
title: Investigating the nature of magnetism by μSR study in the Kondo-lattice  CeRu1-xFexPO (x=0 and 0.8

description: Ce-compounds are well known to present very rich physics and exotic electronic ground state due to the competing RKKY, Kondo and crystal field interactions. Recently CeRuPO attracted attention for its ferromagnetic Kondo lattice behaviour. CeRuPO crystallize in the tetragonal ZrCuSiAs-type structure. At ambient pressure CeRuPO exhibits ferromagnetic ordering at TC = 15 K. Interestingly the ferromagnetic TC is suppressed by Fe-doping in CeRuPO and a ferromagnetic quantum critical point has been observed in Ce(Ru1-xFex)PO near x ~ 0.86. We therefore propose to investigate the microscopic nature of the low temperature magnetism in CeRuPO and the effect of Fe substitution (with x=0.86) using muon spin relaxation (μSR) measurements in zero-field (ZF) and small applied longitudinal fields (LF) to understand the nature and dimensionality of the magnetism in these compounds.
DOI: 10.5286/isis.e.rb1869004
title: Effect of monodispersity on core crystallinity, core packing and nanoparticle morphology of self-assembled block-co-polymers

description: The still unreached goal of nanomedicine is to deliver drugs which are only released in the diseased tissue in a controlled fashion. For this, tailorable, reproducible, and highly controlled drug delivery systems are required. Whereas nature uses discrete building blocks, the current status quo in drug delivery is the use of ill-defined polydisperse macromolecules. Synthetic efforts in material science yielded discrete macromolecules which have astonishingly different properties than their polydisperse counterparts. Here the self-assembly of discrete block-co-oligomers in water is compared to their polydisperse counterparts. Gaining structural insight into these systems will help in establishing the effect of monodispersity on size, architecture, core-crystallinity and packing, all important parameters to control stability and the uniformity of drug release.
DOI: 10.5286/isis.e.rb1720101
title: Examining the properties of water channel in an organic matrix.

description: The objectives are to study the interaction of water molecules held in a channel in an organic matrix. We have structurally characterised a water tetramethylpiperididine complex in which the water molecules allign as essentially micro tubes of water throughout the crystal lattice. We are interested in the detailed structure of this water matrix especially the hydrogen bonding throughout the structure. The reason for the interest is by analogy to nature where water channels are common place. The planned research is to continue to modify the piperidene to allow the formation of water channels in variety of matrixes such as silicates, carbonates, phosphates and memebranes where for example there may be an analogy with capilliaries in bone. Clearly because we are interested in detailed data on the protons and deuterons the best technique is to use neutron diffraction.
DOI: 10.5286/isis.e.rb1720267
title: Quantitative characterization of carbon steel reference samples: creation of a neutron diffraction database

description: The use of quantitative analytical techniques to investigate the properties of steel artefacts is of great importance both in modern and historical metallurgy. A promising approach, but still not fully developed, is the use of neutron diffraction to quantitatively characterize the phase distribution and the micro-structural properties in a non-invasive way. In order to be able to exploit beyond any reasonable doubt this technique, it is necessary to compare the results obtained with analysis from more consolidated techniques in the field of metallurgy. For this purpose, we selected reference samples of certified carbon steel with different composition to be investigated with neutron diffraction. The reference samples will be analysed in three states: as received, after normalization, and after mechanical treatment. Rietveld refinement will provide multiphase and microstructural analysis.
DOI: 10.5286/isis.e.rb1720309
title: Explore the Role of Methyl Groups on Guest Binding in two Metal-Organic Frameworks

description: We seek to develop new stable MOFs for practical separation and storage of CO2 and light hydrocarbons and request 3 days on WISH to study the preferred binding sites of adsorbed gas molecules (CO2 and C2D2-4) within two related MOFs (MFM-305 and MFM-305-deCH3). The role of the CH3 functional group on guest binding has been very rarely characterised experimentally, not least because of the invisibility of the protons by X-ray experiments. The high resolution, low background and large d-spacing capabilities of WISH make it ideal for analysing the precise locations of gas molecules within these porous MOFs and to define the preferred orientations of molecules with respect to the binding sites (i.e.,CD3) on the pore surface. This study will reveal key structural insights into the exciting gas adsorption of these MOFs.
DOI: 10.5286/isis.e.rb1800093
title: The hydration of sucralose

description: We found in our previous experiments (RB numbers 810202 ``Determination of sugar hydration shell and water structure in different water-sugar mixtures''(glucose, fructose, sucrose), 1520061 ``Sweet taste chemoreception unveiled. The case of lactose and sucrose'' and 1520065 ``Sweet taste chemoreception: the strange case of alpha-mannose (sweet) and beta-mannose (bitter)'') that the sweetness of the measured monosaccharides seem to be correlated with the length of the H-bonds between the carbohydrate and water molecules in the first hydration shell (to be published).  To test this hypothesis further, particularly for disaccharides, we would like to measure the hydration of sucralose in water. This would add a fourth point to a three points graph which will hopefully help prove our hypothesis.
DOI: 10.5286/isis.e.rb1810043
title: Molecular Dynamics in Polystyrene

description: A basic understanding of the dynamic processes in polystyrene (PS) is a question of utmost interest and has technological ramifications due to its importance  in commercial products. muSR can provide unique information about molecular dynamics in PS that covers a gap with what is available with other techniques such as neutron scattering or NMR. During our previous experiment (RB1620008) we found that the change in the temperature dependence of the muon spin-lattice relaxation rate (1/T1) may not be due to the glass transition, as previously understood but instead may be due to a change from the deltarelaxation to the gammarelaxation dominating. In order to confirm our previous results and interpretation we need to measure the magnetic field dependence of 1/T1. We will also make measurements at lower temperatures to further study the delta relaxation process.
DOI: 10.5286/isis.e.rb1810050
title: A QENS Study of Guaiacol, a Lignin Model Compound, on a Hydrodeoxygenation Catalyst

description: Bio-oil can be obtained from the pyrolysis of biomass and maintains a closed carbon cycle with no net increase in atmospheric CO2 level, making the environment cleaner. However, the high content of oxygenates in bio-oil result in low heating values, chemical and thermal instability, and immiscibility with hydrocarbon fuels. One effective upgrading process is hydrotreatment using hydrodeoxygenation catalysts. We have synthesised the catalyst with a novel support based on bentonite clays by the pillarization technique, i.e. NiMoS/PILC and results showed that our catalysts were superior to commercial NiMoS/Al2O3. A crucial part of optimising the catalyst is to understand how the reactants move across the surface. To this end, we wish to use quasielastic neutron scattering to study the motion of a lignin model compound, guaiacol (2-methoxyphenol), as a liquid and in the adsorbed state.