cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1800039
title: Improved BAND-GEM detector

description: Most neutron detection systems at spallation sources are based on 3Hedetectors that have an excellent intrinsic efficiency (&gt;70% for thermal neutrons) andcan cover large areas (several m2). Nevertheless the production of 3He from tritiumdecay has declined as the nuclear weapons stockpile has been reduced. This has led toa substantial increase of the 3Heprice preventing its extensive use for researchapplications including future neutron sources such as the European Spallation Source(ESS). Besides the need for replacing 3He,it is essential to develop high-rate neutrondetectors that can fully exploit the increase of neutron flux of ESS compared topresent-day sources. Thus, it is necessary to develop a large area and high-rateneutron detector that does not use 3Hebut has a comparable detection efficiency, anaffordable price and a space resolution of 1-100 mm.
DOI: 10.5286/isis.e.rb1510061
title: Biosurfactant conventional surfactant mixing. Where nature does it better ?

description: Biosurfactants are becoming more commonplace in pharmaceuticals, vaccines and other forms of medicines. With the biobased economy growing substantially and pressure to reduce reliance on palm and crude oil derived materials, it is vital that the Home and Personal Care industry develops frameworks for deploying sustainably sourced alternative materials. Biosurfactants tend to be very similar to nonionic and mild anionic surfactants but with significantly higher molecular weights, generally more than double that of the most commonly used conventional surfactants. By means of studying the structure of the adsorbed layer of biosurfactant conventional surfactant mixtures, in this case using Saponins we hope to gain understanding which can aid in the expansion of the use of these materials towards commodity products.
DOI: 10.5286/isis.e.rb1510119
title: High-energy spin wave excitations in CrAs

description: The discovery of pressure induced superconductivity in non-collinear helimagnet CrAs has generated great interest in understanding its microscopic magnetic properties and their relationship to superconductivity. Our recent neutron diffraction experiment on CrAs has shown that it exhibits a spin reorientation from ab to ac plane along with an abrupt drop of the propagation vector under a critical pressure (Pc~0.6 GPa), where bulk superconductivity emerges. And the Cr moments between nearest neighbors tend to be aligned antiparallel with increasing pressure toward the optimal superconducting regime, suggesting that antiferromagnetic interactions are essential for superconductivity. Therefore, investigation of the spin excitations in the parent compound should give quantitative insight into the relationship between magnetic exchange interactions and superconductivity in this system.
DOI: 10.5286/isis.e.rb1510167
title: Investigating the Surface Structure of Ionic Liquid Mixtures using Neutron Reflectometry

description: The structure of ionic liquid (IL)-gas interfaces is currently a hot topic in the field and understanding of the surface structure of pure ILs is improving. However, very little is known about the surface structure and dynamics of mixtures of ILs. This proposal involves the use of neutron reflectometry measurements to investigate the surface composition and structure of the ionic liquids [EMIM][Tf2N] and [C12MIM][Tf2N] and their binary mixtures. Isotopic contrast variation will be employed in order to probe the surface structure and to investigate the surface activity of the different cations as a function of the bulk composition. These data, alongside SANS measurements and complementary reactive-oxygen-atom scattering experiments, will enable a detailed understanding of nano-segregation and structuring effects (in both the bulk and at the surface) in these IL mixtures.
DOI: 10.5286/isis.e.rb1510379
title: Comparative Interaction Studies of Antimicrobial Agents on Bacterial Membrane Models Containing either Smooth and Rough Lipopolysaccharides

description: The outer membrane (OM) of Gram-Negative bacteria (GNB) is an asymmetric structure which contains complex lipids known as lipopolysaccharides (LPSs) on the outer surface. LPSs comprise the membrane anchoring Lipid-A, the anionic core oligosaccharides and the very large, solution facing O-antigen which acts as a hydrophilic barrier to antibiotics. We intend to deposit LPS on OTS coated silicon surfaces as a model OM. Using this system we will be able to deposit smooth LPS, a more complete form of the molecule than deposited previously as it contains the O-antigen. We the aim to examine the interactions of two antimicrobial agents which interact with the core of the OM in their killing activity with the OM model containing smooth LPS and compare this to a model containing the O-antigen free rough LPS to determine the role of the O-antigen in bacterial defence against antimicrobial agents.
DOI: 10.5286/isis.e.rb1510406
title: Investigating the structure of the pulmonary lung surfactant at the air-water interface

description: The lung surfactant is a film coating the alveolus of the lung. We want to characterize the structure of this film at the air-water interface at a molecular level. This will give us crucial information on the structural importance of the lung surfactant in a healthy lung. To do this characterisation we need to use neutron reflectometry for an unambiguous determination of the thickness of the film and how this changes with cholesterol and Ca2+ ions. We want to mimic the conditions in the lung by having a controlled humidity close to 100% at 37 °C. We want to follow the film formation over time and investigate the structural changes with repeating compression ¿ expansion cycles imitating the work of breathing. We want to do this study on both a clinical extract used to treat infants with respiratory distress syndrome and an extract of the endogenous lung surfactant of the new-born baby.
DOI: 10.5286/isis.e.rb1510445
title: In-gap excitons in CaFe2O4

description: The proposal requests time to measure the low-energy excitations in CaFe2O4 as a function of temperature.  Previous experiments have observed a series of in-gap states at high temperatures and the experiment will track the temperature dependence of these.  OSIRIS is required given the good energy resolution.
DOI: 10.5286/isis.e.rb1510506
title: Graphene Surface Functionalisation Effect on Hydrogen Spillover

description: Hydrogen spillover involves dissociation of molecular hydrogen at the surface of metals, particularly transition metals, followed by migration of the hydrogen atoms across the surface which in this case is few-layer graphene. Surface functionalisation, particularly oxygen functionalisation of graphene has been shown to increase this effect, but the mechanism is not known. In-situ, inelastic neutron scattering studies can distinguish between weakly bound hydrogen atoms, physically bound hydrogen molecules and chemically bound hydrogen atoms including differentiating hydrogen atoms that are in clusters of up to three hydrogen atoms in nearest-neighbour configuration. Using few-layer graphene¿s doped with platinum nanoparticles and exhibiting surface oxygen content ranging from 7-30 wt.%, we will study the spillover mechanism with the aim of elucidating the bound state of hydrogen atoms.
DOI: 10.5286/isis.e.rb1510541
title: Adsorption of Alkylphenols onto the Surface of Polyamide-imide from Oil

description: Polyamide-imides are an important class of engineering polymers whose applications often call for high wear resistance whilst maintaining suitable lubrication. An understanding of the adsorption of molecular species onto this surface is crucial in the development of new and ever more effective lubricants. Alkylphenols are a common basis for many commercial lubrication additives and so were chosen as the molecular species for this investigation. Here we aim to directly investigate the adsorption of various alkylphenols onto a polyamide-imide surface by neutron reflection. We propose to study the adsorption of phenol, 4-n-butylphenol and 4-n-octylphenol at various concentrations as well as a full characterisation of the final monolayer. This will allow us to judge the effect that the alkyl chains have on both the formation and structure of the monolayer.
DOI: 10.5286/isis.e.rb1600002
title: Disordered ice II  a possible new ice phase
DOI: 10.5286/isis.e.rb1610057
title: Role of acidic silanols and Brønsted acid sites in hierarchically porous SAPO-34 for the production of eta-caprolactam - TOSCA

description: The commercially important polymer Nylon 6 is manufactured by ring-opening polymerization of eta-caprolactam. Industrially, eta-caprolactam is conventionally made by the Beckmann rearrangement of cyclohexanone oxime, a stoichiometric process that generates large quantities of undesirable by-products. Recent work at Southampton has shown that a hierarchically porous silicoaluminophosphate; HP-SAPO-37, is able to achieve near-quantitative yields of eta-caprolactam at temperatures as low as 130 °C. The interaction of the oxime with acidic silanols and Brønsted acid sites is crucial to the mechanism but this is not well-understood. The aim of this proposal is to investigate a series of catalysts with different types of acidity in order to characterise how the interaction of cyclohexanone oxime varies with the different acid groups and hence provide insight into the reaction mechanism.
DOI: 10.5286/isis.e.rb1610230
title: Anomalous magnetism in oxygen-deficient scandium-doped spin ice

description: Our previous diffuse neutron scattering experiment on SXD showed that oxygen vacancies are the dominant defects in spin ice. The substitution of tetravalent titanium by trivalent scandium requires oxygen vacancies for charge neutrality. This provides the means to achieve oxygen depletion in a more controlled manner. It is also possible to increase the degree of oxygen deficiency so that correlations between vacancies may be expected, increasing the likelihood of new cooperative phenomena. The difference in the ionic radii of scandium and titanium introduces local strains, and we find an anomalous effect on the magnetic susceptibility. We propose to determine the defect structures in scandium-doped spin ice using diffuse neutron scattering on SXD. The results will be compared with DFT and used to calculate crystal field effects in order understand the anomalous magnetism.
DOI: 10.5286/isis.e.rb1610240
title: Perylene Bisimide Photocatalysts

description: Solar energy is the most abundant, sustainable, and environmentally friendly source of energy available on the earth. One promising approach to reducing the reliance on fossil fuels is to generate H2 and O2 by the photocatalytic splitting of water. Whilst there are significant data on inorganic materials that can be used for hydrogen evolution from water and overall water-splitting, there is relatively little information available for organic-based systems. Organic photocatalysts are interesting as they are potentially a very low cost technology, based on earth abundant elements, and more tunable than inorganic systems. There has been a surge of interest recently in light-driven water splitting using organic rather than inorganic photocatalysts. Here, we will examine a range of perylene-based photocatalysis, aiming to link the structures to the activity.
DOI: 10.5286/isis.e.rb1610478
title: Measurement of surface diffusion on Raney nickel

description: Many catalysts work by adsorbing molecules onto their surface to from a more concentrated phase, which increases the likelihood of reactants colliding, and reacting to form a new product. I want to measure the nature of the molecular motion in the condensed, surface phases of benzene and cyclohexane on nickel to illuminate the nature of these constrained reactants.
DOI: 10.5286/isis.e.rb1610520
title: Negatively Charged Muons as an Elemental Probe for the Carbon Composition of Archaeological and Art objects.

description: Proof of principle of the use of negative muons as a non-destructive elemental probe have been provided  by recent trial experiment on the RIKEN_RAl muon facility. We propose to explore this analytic tool to determine the carbon content in bloomer iron test sample and plate armour of the period 1550 -1650 AD as well as the compostion of brass/ bronze alloy and its core filling in 2 small Renaissance bronzes, attributed to François Duquesnoy.
DOI: 10.5286/isis.e.rb1620018
title: Solvation and structure of iron oxide in a choline chloride/oxalic acid deep eutectic solvent

description: We aim to investigate the solvation of iron oxide and zinc oxide in an environmentally friendly deep eutectic solvent system in order to understand how to engineer these new solvents to selectively recover valuable components from waste sources such as red-mud, the residue left from aluminium production.
DOI: 10.5286/isis.e.rb1620063
title: Unraveling the structural ordering of water in amorphous calcium carbonate (ACC) using neutron pdf-analysis II

description: Carbonates and phosphates are highly important in biomineralization. They are found as hydroxyapatite (Ca5(PO4)3OH) in bone or calcite/aragonite(CaCO3) in seashells and corals.These biogenic minerals are commonly formed from amorphous precursors (APs). To control the properties of the AP, foreign ions are incorporated to increase stability and direct polymorph selection. In a previous experiment we have studied amorphous calcium carbonate (ACC) with Neutron/x-ray pdf and EPSR and found structural similarities between water molecules and calcium ions in ACC and that of a Ca ion in solution. We now would like to extend this study to a mixed phase calcium carbonate/phosphate (ACCP) of defined composition to understand how the structural relation between the ions is affected by the presence of a foreign anion.
DOI: 10.5286/isis.e.rb1620154
title: In-situ under electric field neutron diffraction at variable (low) temperatures on BiFeCoO3-Bi0.5K0.5TiO3 ceramics

description: Neutron diffraction experiments will be carried out on multiferroic ceramics. What is special about the measurements, is that they will be carried out under an applied electric field. It is difficult to perform such measurements with neutrons, because a particularly high vacuum is necessary, which is one of the special features of the requested instrument. However, such a measurement is very valuable to study the magnetoelectric properties of the sample. In previous experiments, it was found that the material exhibits extraordinary and strong magnetoelectric coupling properties.. It is the aim of the proposal to study the magnetic structure with neutron diffraction while applying an electric field and thus gaining insight into magnetoelectric coupling in particular between so called polar and magnetic nanoregions. The coupling is important for research on computing and sensor materials.
DOI: 10.5286/isis.e.rb1620257
title: Magnetic excitation spectrum of a potential spin liquid candidate

description: PbCuTe2O6 consists of a 3-dimensional arrangement of spin-1/2 Cu ions. There are 3 potentially strong interactions, the first neighbor interaction couples the magnetic ions into isolated triangles, the second couples them into the highly frustrated hyperkagome lattice consisting of corner sharing triangles and the third neighbor interaction couples them into antiferromagnetic chains. In PbCuTe2O6 the hyperkagome interaction dominates suppressing long-range magnetic order making it a promising spin liquid (SL) candidate. The fundamental excitations of a SL are expected to be spinons which are fractional (spin-1/2) excitations and are observed in inelastic neutron scattering (INS) as broad and diffuse features rather than the sharp modes typical of magnons or spin-waves. In this context, we wish to explore the magnetic excitations of PbCuTe2O6 using INS on LET spectrometer.
DOI: 10.5286/isis.e.rb1620449
title: SANS Studies of Radiation-grafted Anion-exchange Membranes with Different Grafting Times

description: We request one days beam time on SANS2D for the study of hydrated, radiation-grafted anion-exchange membranes synthesised with different grafting times. These materials are some of the most promising anion-exchange membranes for use in energy applications (such as fuel cells and water electrolysers). Ionic conductivity varies significantly with grafting time, whereas ion exchange capacity remains constant, therefore it is proposed that the changes in the hydrated membranes morphologies is responsible for the differences in conductivity. We propose to collect SANS data for membranes with five different grafting times in order to elucidate the connection between ionic conductivity and mesoscale morphology.
DOI: 10.5286/isis.e.rb1661007
title: Optimization of neutron scattering and absorption properties of new types of concrete slabs to be used as shielding material for ESS
DOI: 10.5286/isis.e.rb1670523
title: Quantum fluctuations in iron-pnictide supercondcutors BaFe2(As1-xPx)2
DOI: 10.5286/isis.e.rb1710279
title: Overcoming Chemical Reaction Equilibrium: Determining the Chemical Potential In-Situ in a Chemical Looping Reactor

description: We have developed and demonstrated a novel process to overcome chemical reaction equilibrium constraints on an important reversible industrial chemical reaction by using chemical looping with a non-stoichiometric oxygen-carrier material. We have successfully probed the lattice parameters of the oxygen-carrier material along the length of a lab-scale working reactor bed (12 cm length) in full operation on ID22 at ESRF which proves the principle of operation. The ability to correctly model the thermodynamic parameters of this material will allow for industrial scale implementation of this unprecedented technique. In order to determine the local chemical potential of the solid phase along the length of the reactor bed we must establish the relationship between oxygen occupancy, lattice parameter, and chemical potential as a function of oxygen partial pressure and temperature.
DOI: 10.5286/isis.e.rb1710308
title: Study of quadrupolar interactions in aromatic liquids: Benzene, hexafluorobenzene and 1,3,5-trifluorobenzene.

description: The non-covalent interactions between aromatic rings are of fundamental importance in large number biological and chemical processes. Examples include protein tertiary structure, DNA base stacking, supramolecular chemical recognition, crystal engineering and petroleum phase behaviour. The local structure of aromatic liquids is a delicate balance between dispersion attraction and electrostatic forces due to the uneven distribution of charge over the molecules. An excellent model system with which to study the effect of charge distribution in aromatic liquids is hexafluorobenzene, which has a similar properties (boiling and melting points) and structure to benzene but with an opposite distribution of charge. Here we will study changing this charge distribution effects the local arrangement of molecules in benezene:fluorobenzene mixtures.
DOI: 10.5286/isis.e.rb1710471
title: Multiferroic properties of organic ferroelectrics revealed using muons

description: The study of organic ferroelectrics based on mixed-stack charge-transfer salts is currently a rapidly developing research field. These materials attract interest as highly tailorable ferroelectrics whose dielectric properties include a strong contribution from an electronic charge transfer mechanism that operates alongside the more conventional ionic displacement mechanism. The prototype for this type of system is TTF-CA which combines the electron donor molecule TTF with the electron acceptor molecule p-chloranil (CA). The ferroelectric transition is at Tc=81 K and is accompanied by a neutral-ionic transition and a dimerisation of the chain.  Our ongoing muon studies have revealed a wealth of information on this system and have identified a hidden magnetic character to this ferroelectric transition, consistent with previous predictions of it having an underlying multiferroic nature.
DOI: 10.5286/isis.e.rb1720250
title: Investigation of spin-Hamiltonian of the quasi-1D trimer spin-chain compound CaNi3P4O14

description: Among the spin-trimer compounds AM3(P2O7)2 (where A=Ca, Sr, Ba, Pb and M=Co, Mn, Ni), only the Mn based compounds (with S=5/2)  exhibit the 1/3 magnetization plateau, whereas, no such magnetization plateau is found for the isostructural Co (S=3/2) and Ni (S=1) based compounds having low spin values. We propose an inelastic neutron scattering study on the quasi-1D trimer spin-chain compound CaNi3P4O14 to understand the physics behind the absence of 1/3 magnetization plateau and to determining the spin Hamiltonian (the exchange constants and anisotropies) in this spin trimer system. Crystal field excitation spectra will be also measured to understand the origin of the single-ion-anisotropy and orbital moment in the compound.
DOI: 10.5286/isis.e.rb1720263
title: Copy of: Magnetic and lattice excitations in the magnet-caloric family Mn(5-x)Fe(x)Si3

description: We propose to map out magnetic and lattice excitations in compounds Mn(5-x)Fe(x)Si3.Varying the Fe content, the system shows a tunable magneto-caloric effect, both in the magnetic entropy change as well as in the temperature range. We have recently shown, that magnetism and lattice are coupled dynamically as evidenced by anisotropic changes in the lattice expansion and the elastic constants upon crossing the Curie temperature Tc. Furthermore this compound also follows the recently suggested paradigm that a large magneto-caloric effect is promoted by different crystallographic sites occupied by the magnetic ions. In particular we would like to study in this experiment the system with x=2, where one site is nearly completely occupied by Mn and the other by Fe. In detail we would like to map out the excitation spectrum of a single crystal at temperatures T=10K and T=100 K.
DOI: 10.5286/isis.e.rb1720315
title: Temperature Dependent Single Crystal Neutron Diffraction Study of the Hydrogens Dynamics in a Hydrido-Complex of Iridium.

description: Transition metal hydrides are involved in many stoichiometric and catalytic organometallic reactions, such as hydrogenation. In these reactions the crucial step in the reaction path is the co-ordination of an intact H2 molecule to the metal centre and the ligand-dynamics of the resulting coordination compound.  We propose to carry out an accurate single crystal neutron diffraction study on the octahedral complexes trans-[(P iPr3)]2IrI(H)2(H2) to investigate the temperature dependence of the ADPs. Our aim is to obtain insight on the relationships between the large amplitude motion of the H atoms, the exchange mechanism between H and H2 and the rapid reversible absorption/desorption equilibrium.
DOI: 10.5286/isis.e.rb1720360
title: Investigation of the singlet ground states in PrT2Ga8 (T=Fe, Co) compounds

description: We are interested in investigating the nature of the ground states in the two titled compounds. Based on theoretical predictions, no magnetic ordering is expected in these compounds. However, we have found out that both compounds show a magnetic ordering at low temperatures. This we think might be due to an induced type of magnetism which might results under certain conditions. We will be requiring INS experiment to be able to better understand what is responsible for the behavior we have seen in these two compounds. We are hoping our results from INS will help to better understand the emergence of magnetism in both compounds and we further intend to extrapolate these results to explain similar behavior in other systems we are investigating.