cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1410358
title: E/T scaling and quantum critical fluctuations in Sr3Ru2O7

description: Many novel electronic ground states form in close proximity to quantum critical points (QCPs), that is, the point where a continuous phase transition occurs at zero temperature. By suppressing the second-order metamagnetic transition in Sr3Ru2O7 to low temperatures with a magnetic field, the system can be driven into a new and highly unusual electron-nematic phase (ENP) which exists below approximately 1 K in a field of approximately 7.95 T. Here we propose to determine whether the magnetic excitations obey "E/T scaling" at the critical field and for temperatures approaching the  NP. "E/T scaling" of the magnetic excitations would demonstrate the magnetic nature of the quantum critically and underlying order parameter of the ENP.
DOI: 10.5286/isis.e.rb1410437
title: Mass-selective Neutron Spectroscopy of Molten FLiBe

description: We request time on VESUVIO to study the properties of FLiBe using mass-resolved neutron spectroscopy (MANSE). FLiBe is a mixture of BeF2 and LiF and its physical properties in the liquid state resemble those of water. The low melting point of the eutectic mixture (630 K) makes it a promising solvent for molten-salt-reactor technologies, yet its microscopic properties under operating conditions remain largely unexplored. This proposal seeks to fill the above gap by providing direct and simultaneous access to the mean kinetic energies of all three nuclides. On the scientific front, these data will provide stringent benchmarks for first-principles calculations on this technologically relevant material. From an instrumentation point of view, these experiments will also serve to assess in detail current capabilities on VESUVIO to perform MANSE studies on ternary mixtures of light elements.
DOI: 10.5286/isis.e.rb1510104
title: Drug solvation in amphiphilic solutions: understanding how small molecules cross the blood brain barrier

description: Understanding how drugs interact with physiologically relevant environments is crucial for the future of effective drug design. An important class of potential drugs are central nervous system (CNS) drugs which need to cross the blood brain barrier (BBB) in order function.  In the current work, we propose to investigate the solvation structure of drugs which cross the BBB in model environments which mimic the hydrophobic/hydrophilic interface of the BBB.
DOI: 10.5286/isis.e.rb1510115
title: Investigation of low temperature magnetic structure in vanadium dioxide compounds

description: We propose a study of the low temperature magnetic structure of vanadium dioxide (VO2) compounds using long-wavelength neutron diffraction measurements. This study directly compliments a series of Muon Spin Rotation and Relaxation measurements that recently uncovered a never before reported magnetic phase. the MuSR measurements directly measure the magnitude of the local field and associated dynamics but are not capable of producing information related to magnetic structure. these proposed neutron measurements focus specifically on the low temperature regions to explore the magnetic structure thereby providing a more robust picture of this magnetic phase. Understanding the low temperature magnetic phases may also provide insight into the fundamental mechanisms responsible for the various, yet to be understood, transitions present in these VO2 compounds.
DOI: 10.5286/isis.e.rb1510465
title: Deep Eutectic Solvents: Metal Ion Dissolution

description: Deep Eutectic Solvents (DES) are molecular mixtures similar to ionic liquids, having melting points below room temperature. However instead of being composed of a salt, the mixture contains two molecules with strong interactions that hinder formation of an ordered crystalline network. DES share many of the features of ionic liquids (low vapour pressure, adjustable polarity, etc) which make them interesting as green solvents while being far less toxic than typical ionic liquids. They are also good solvents for metal salts meaning they have potential as non-aqueous solvents for surfactant templated syntheses of porous inorganic materials which form from water-sensitive precursors. Here we propose to study the structure of the most commonly studied DES, choline chloride:urea, with and without catalytic amounts of water and Ce(NO3)2, a cerium oxide precursor.
DOI: 10.5286/isis.e.rb1510476
title: Magnetic Structure and Martensite Twin-Laws of ferromagnetic Co2-Ni-Ga and Fe-Ni-Co-Al-Ta Shape Memory Alloys

description: Pseudoelastic, ferromagnetic Co2NiGa type high-temperature shape memory alloys (HT-SMAs) are characterized by a wide range of tunable transformation temperatures and lower processing costs compared to conventional Ni-Ti-X HT-SMAs which renders them useful for high-temperature applications in automotive and aerospace industries. Pseudoelastic FeNiCoAlTa magnetic shape memory alloys can be produced at even cheaper costs and are interesting SMAs for applications at ambient temperatures. Despite those materials' relevance for future applications, their magnetic space group, the amount of chemical ordering and martensite twin-laws have not yet been determined experimentally. In this proposal we would like to focus on magnetic structures of all phases and twin laws of martensite phases to better understand fundamental aspects and fatigue behaviour of CoNiGa and FeNiCoAlTa.
DOI: 10.5286/isis.e.rb1510513
title: New Ruthenium-based dyes for environmentally friendly optical devices

description: The cis-[Ru(bipy)2(PTA)2]Cl2, trans-[Ru(bipy)2(PTA)2]OTf2  ruthenium complexes are highly water soluble and luminescent in water at room temperature. Additionally, their optical properties show a pH and temperature dependence and they show reversible redox properties in water. These complexes are eligible candidates to be inks in dye-solar cells but also good candidates for being catalysts in useful processes such as photochemical water oxidation or/and hydrogen generation from water. Particularly relevant in the context of this proposal is understanding the relationship between molecular structure/isomerism and charge distribution, and how water affects both. The novelty resides in the fact that these molecules would open the way to new water-based, green optical devices.
DOI: 10.5286/isis.e.rb1510518
title: A comparative study of tricriticality in CoMnSi and NiMnGe

description: We propose to use WISH to examine whether a transition between different spiral antiferromagnetic structures in zero magnetic field is the key to tricriticality at finite fields in CoMnSi and NiMnGe.  We seek to correlate the temperature evolution of the magnetic structure in both compounds with their different magnetic phase diagrams and with the observation (in CoMnSi) or absence (in NiMnGe) of large entropy changes at a magnetic tricritical point.
DOI: 10.5286/isis.e.rb1520456
title: Verification of residual stress induced by the centre-hole-drilling method when applied to ASTM F-75 (CoCr alloy)

description: ASTM F-75 is a standardised material for implant use and is widely used for components which have moving-contact surfaces, i.e. femorals. ASTM F-75 (CoCr) prosthetic knee implants, specifically femoral components, distort inconsistently as a result of redistributed Residual Stress (RS) during grinding. Centre-Hole-Drilling (CHD) has been applied to ASTM F-75 femorals, but problems occurred with the drill stalling and poor geometry holes. A technique applied by Veqter, utilising a dental burr and spindle speeds in the region of 10k rpm driven by an electric motor,  proved successful in inducing a square edge, flat bottom hole. But it is currently unknown what level of stress is induced by this drilling method. It is proposed to perform ND experimentation on samples with stress relieved by annealing and uniform plastic deformation, to compare with and verify CHD results.
DOI: 10.5286/isis.e.rb1610108
title: Apatite-type Oxides for Energy Applications:  Role of Lattice Dynamics

description: Lanthanum-containing germanate apatites are materials with potential applications as electrolytes in solid oxide fuel cells. The conductivity of these materials is known to depend greatly on the precise composition and structure (and hence on defects and the conduction pathways available). Recent computational work suggests that electronic factors are also important. We have prepared a series of materials in which La3+ is systematically partially replaced by Bi3+ (of very similar size, but an electron lone-pair containing cation). Ab-initio molecular dynamics simulations are being performed to investigate the significance of these electronic effects induced by chemical substitution, and we need to support these with direct observation of oxide ion dynamics through inelastic and quasielastic neutron scattering. For this experiment we request 4 days of beamtime on LET.
DOI: 10.5286/isis.e.rb1610302
title: Proof of concept study on the effect of pre-adsorbed hydrocarbon on the transport of ammonia within an industrially relevant zeolite

description: Diffusion of ammonia within zeolites is of great interest due to applications in the selective catalytic reduction (SCR) reaction in fuel exhausts, reducing harmful NOx compounds to nitrogen. Though this system has been studied previously with small pore zeolites (showing that the presence of a counter ion affects ammonia diffusivity), a real system involves the presence of hydrocarbons in the catalyst which competitively diffuse with ammonia. This proposal aims to measure the effect of the presence of a long and short alkane (deuterated to remove their signal) on the diffusion of ammonia in commercial SCR catalyst zeolite Beta. The metal free zeolite is chosen because counter ion presence was shown previously to affect diffusion. Two loadings of the alkane will be chosen (1 mol/uc and 3 mol/uc) to judge the affect of both concentration and chain length in hindering ammonia diffusion.
DOI: 10.5286/isis.e.rb1610323
title: Search for skyrmion phases in GaV4X8 (X=S, Se,Te)

description: One exciting avenue of research in condensed matter has focused on the physics of topological objects called skyrmions. Recently, the existence of magnetic skyrmions or skyrmion lattice has been reported in materials with a different chiral space group from that of B20 compounds, such as GaV4S8. In this proposal we plan to extend our investigations of the GaV4X8 (X = S, Se, Te) family of compounds by means of small angle neutron scattering experiments. The systems we have chosen are GaV4Se8, GaV4S4Se4 and GaV4Se4Te4, which have similar physical properties to GaV4S8 and are potential candidates for hosting magnetic skyrmion states. The field and temperature range of the possible skyrmion phase in these materials makes it suitable to be probed using Sans2d spectrometer.
DOI: 10.5286/isis.e.rb1610378
title: Redistribution of residual stress state by lateral rolling of components produced by wire plus arc additive manufacture (WAAM)

description: Wire + Arc Additive Manufacturing (WAAM) is a  digital tool less manufacturing technique that uses traditional arc welding power sources and a robotic system, to build large three-dimensional metallic components and structures. This manufacturing tool provides high recovery of deposition as opposed to traditional subtractive machining. However, the thermal stress generated during such process would remain locked-in as self-balancing residual stress and would result in distortion of the component which would depend on the geometry and dimension of the component. Rolling, as means of local mechanical tensioning, could be an effective way to remove such localised stress and subsequently the distortion will be eliminated. The present proposal would investigate the effectiveness of lateral rolling process and roller geometry in redistributing the stress field and eliminating distortion.
DOI: 10.5286/isis.e.rb1620058
title: Correlated O/N orders in melilite phosphors

description: Red or yellow phosphors excited by a blue light-emitting diode (LED) are an efficient source of white light for everyday applications. Melilite type Y2Si3O3N4:Ce3+ is a phosphor that shows intense absorption in the near ultraviolet region and exhibits bright blue emission3 because of this it is a promising blue-emitting phosphor candidate for white LEDs for general illumination or displays. We request 2 days on GEM to collect total scattering data for two 3g samples at room temperature. One sample will be Y2Si3O3N4 and PDF analysis will be used to examine local arrangements of O/N.  The second sample will be Ce0.5Y1.5Si3O3N4 where local clustering will be explored. This has important implications for the photoluminescent properties as a coordination environment richer in O and poorer in N leads to a blue shift of the emission spectrum.
DOI: 10.5286/isis.e.rb1620213
title: Mapping the elastic strain field around a fatigue crack using Bragg edge mapping

description: The effects of notches on the fatigue life of components have long been investigated and methods a proposed that semi-empirically account for the notch. They are concentrated on estimation of the fatigue limit stress.  but the effect of the notches on fatigue crack initiation has been less investigated due to lack of suitable non-destructive tools. Despite the qualitative studies on the size effects on fatigue crack initiation, few quantitative studies can be found in literature since identification of fatigue crack initiation, which often occurs inside notched coupons, has so far been an arduous task. We propose a critical Bragg edge mapping experiment at EnginX to identify the onset of fatigue crack initiation in round notch bars with varying crack lengths. We will complement this work with neutron tomography and digital volume correlation, should IMAT be ready to receive users.
DOI: 10.5286/isis.e.rb1620261
title: Cation and spin orders in double double perovskites

description: Our recent neutron study showed that CaMnFeReO6 has a recently discovered double double perovskite structure type with cations ordered across 3 distinct A-sites in columns while B-cations order in a rock-salt structure. To explore whether cation ordering across all five different crystallographic sites is possible we have synthesised two new materials which adopt this same structure type: CaMn0.5M0.5FeReO6 (M = Cu and Fe). Magnetisation data for CaMn0.5Cu0.5FeReO6 shows a high TC of 560 Kand  a second A site spin ordering transition at 175 K. Two days of WISH beamtime are requested to establish crystallographic and magnetic structures. These materials are prepared by high pressure and temperature syntheses with a Walker-type multi-anvil module. Sample size is therefore limited and 60 mg polycrystalline samples will be used for data collection at a few temperatures between 10 and 300 K.
DOI: 10.5286/isis.e.rb1620329
title: Negative thermal expansion in ReO3: anomalous variation with temperature

description: ReO3 is a well-known oxide framework with unusual thermal expansion behaviour, exhibiting multiple regions of both positive and negative thermal expansion (NTE). We propose to investigate its local structure using total neutron scattering. We will analyse the resulting data using the reverse Monte Carlo method, with an emphasis on understanding the rigid unit mode fluctuations associated with NTE. The analysis will construct the distribution of atomic positions associated with these fluctuations, and from its temperature dependence we will be able to observe the effects of the anharmonic effects that must be the physical origin of the anomalous NTE behaviour. Comparison with ongoing analysis of the isomorphic material ScF3 will give new insights into the behaviour of these archetypal NTE materials.
DOI: 10.5286/isis.e.rb1620352
title: Using negative muons as a non-destructive probe of material composition

description: Elemental analysis is a process in which a sample is analysed for its composition. Often this is accomplished by destructive and damaging techniques. Clearly, such techniques are not desirable for valuable items (either scientific or monetary). Therefore, techniques of non-destructive bulk elemental analysis are desirable, for example in engineering, Earth and archaeological sciences. Negative muons offer the possibility of a non-destructive multi-elemental analysis.
DOI: 10.5286/isis.e.rb1710059
title: Magneto-orbital coupling in PbMn7-xFexO12

description: The interplay between orbital order and magnetism in insulating manganites has been extensively studied following the seminal neutron diffraction experiments of Wollan and Koehler in the 1950s. Recently, we have shown that AMn7-xFexO12 quadruple perovskites display a novel magneto-orbital coupling of greater complexity than that previously observed, which we can explain through a universal model. Importantly, our model predicts coupling between orbital and magnetic degrees of freedom in all antiferromagnetic phases. However, if A =Pb, we have found an intermediate phase in which the coupling is destroyed. Further, by substituting Fe for Mn, the magneto-orbital ground state is suppressed altogether. Here, we propose a neutron diffraction experiment to solve the magnetic structure of PbMn0.69Fe0.1O12 in the decoupled phase, from which we will be able to refine our model.
DOI: 10.5286/isis.e.rb1710115
title: Effects of Non-Steroid Anti-Inflammatory Drugs on the Microscopic Dynamics of DODAB based Lipid Membrane

description: Dioctadecyldimethylammonium bromide (DODAB), is a double chain synthetic cationic lipid that conforms the membrane-like bilayer structure and has found widespread use in several biomedical applications. Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs for their pain reducing and anti-inflammatory action. Different NSAIDs, having similar chemical structure, show different biological impact and their therapeutic effects. The mechanisms leading to these differences should be related to their interaction with the biological membranes which can change the structure and dynamics of the membrane system significantly. To investigate the change in dynamical behavior of lipid molecules due to drugs-membrane interaction, we would like to perform the QENS study on the DODAB membrane with three prominent NSAIDs namely aspirin, ibuprofen and indomethacin.
DOI: 10.5286/isis.e.rb1710198
title: The effect of alkyl side chain addition on the intermolecular vibrational modes in high charge carrier mobility molecular semiconductors

description: Carbon based organic semiconductors offer the ability to create advanced electronics with materials that can be processed from solution through low cost and high volume methodologies such as printing. However, because these molecules are held together by weak forces, they can undergo intermolecular vibrations. These vibrations are thought to modulate the electronic coupling between molecules and therefore localise charges on single units on very short time scales, reducing the effective mobility. To date, little work has been done in understanding how molecular design can be used to suppress these vibrations and therefore boost the charge carrier mobility. Our group has previously theoretically identified long axis alkyl chain addition as a methodology to suppress these modes. Therefore, our proposal aims to quantify this effect in two classes of top performing organic semiconductors.
DOI: 10.5286/isis.e.rb1710381
title: Low-energy magnetic excitations in the superconducting state of Sr2RuO4: opening of a gap?

description: We propose to study the magnetic fluctuations of the unconventional superconductor Sr2RuO4 in the superconducting state extending our previous experiments on a cold triple-axis spectrometer. First, we wish to study the gap opening in the magnetic excitataions associated with the nesting of the one-dimensional alpha and beta bands. From our previous work we know that such a gap is well beyond the currently accepted values of 2Delta. In addition we propose to search for a response of the quasi-ferromagnetic fluctuations related to the van Hove singularity of the two-dimensional band, which seem to play a stronger role in the superconducting pairing.
DOI: 10.5286/isis.e.rb1710424
title: Using SANS to understand the structural basis for the rheology of molten chocolate

description: Molten chocolate is a semi-solid suspension of (mostly) sugar, but also cocoa and milk solids in oil. In order to allow the sugar grains to flow past each other, either when the chocolate is being made, or when it has melted in your mouth, it also contains additives known as surfactants. These are mostly naturally occuring products, such as lecithin, which is comprises lipids which are found at surfaces in nature, but also some polymeric molecules such as PGPR. We will use the technique of small angle neutron scattering to gain the structural information to test a model we have derived using polymer physics to explain how they lubricate the sugar grains and hence make nicer, healthier and cheaper chocolate.
DOI: 10.5286/isis.e.rb1710468
title: Probing the local structure of entropy-stabilised oxides

description: The proposed experiment involves the local-structural characterisation of a new class of functional material: the entropy-stabilised oxide. These are mixtures of 5 or more simple oxides which, if left to their own devices, would form slightly different crystal structures, but when they are heated together they surprisingly form a single phase. This is thought to be because the large amount of entropy (basically a measure of how disorganised something is) in a random mixture overcoming the unfavourable interactions between metals that don't normally hang out together. These materials are likely to exhibit a wide range of properties and have a wealth of applications, but an in-depth understanding of their structure, such as that obtained from total neutron scattering, is required for their potential to be fully realised.
DOI: 10.5517/ccdc.csd.cc21b1k0
title: CCDC 1886491: Experimental Crystal Structure Determination

description: Related Article: Yujie Dong, Junjie Shen, Weijun Li, Ruiyang Zhao, Yuyu Pan, Qingbao Song, Cheng Zhang|2019|Tetrahedron|75|2670|doi:10.1016/j.tet.2019.03.041
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.cc21b96x
title: CCDC 1886728: Experimental Crystal Structure Determination

description: Related Article: Thomas Müntener, Fabienne Thommen, Daniel Joss, Jérémy Kottelat, Alessandro Prescimone, Daniel Häussinger|2019|Chem.Commun.|55|4715|doi:10.1039/C9CC00720B
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.cc21b97y
title: CCDC 1886729: Experimental Crystal Structure Determination

description: Related Article: Thomas Müntener, Fabienne Thommen, Daniel Joss, Jérémy Kottelat, Alessandro Prescimone, Daniel Häussinger|2019|Chem.Commun.|55|4715|doi:10.1039/C9CC00720B
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.