cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25835/0067125
title: Signatures of non-Abelian anyons in the thermodynamics of an interacting fermion model

description: Plots, data and Mathematica notebooks for the paper:\r\n\r\nDaniel Borcherding and Holger Frahm (2018): Signatures of non-Abelian anyons in the thermodynamics of an interacting fermion model, J. Phys. A: Math. Theor. 51 195001 \r\nDOI: https://10.1088/1751-8121/aaba1e \r\narXiv: 1706.09822\r\n\r\nand the doctoral thesis:\r\n\r\nDaniel Borcherding (2018): Non-Abelian quasi-particles in electronic systems. Gottfried Wilhelm Leibniz Universit\xe4t Hannover, Diss.\r\nDOI: https://doi.org/10.15488/4280
DOI: 10.5286/isis.e.rb1620017
title: The magnon density of states in NiPS3

description: NiPS3 is a magnetic material.  Its structure has similarities to graphite in that the atoms are strongly bound in planes but the planes are only weakly bound.  It is called "quasi-two-dimensional" for this reason.  Its magnetism is also quasi-two-dimensional, with strong magnetic interactions within the planes and only weak interactions between the planes.  This makes it potentially very useful to test detailed theory models for magnetism in two dimensions.  We wish to use neutron inelastic scattering to measure the magnetic fluctuations within the compound, to determine the strength of the intra- and interplanar interactions and thus to be able to test quantitatively the theories that describe low-dimensional magnetism.
DOI: 10.5286/isis.e.rb1620277
title: Single proton short time dynamics in Pd/Ag membranes

description: Pd-Ag membranes used in Fusion machines for isotopic separation of H isotopesa can also be used for the production of ultrapure H with interesting applications in renewables. Neutron diffraction and inelastic scattering experiments have been done on Pd/Ag (77:23) at ILL (D1B) and ISIS (MARI), respectively, aiming at assessing the structure of the deuterated material and the density of the vibrational states projected on the proton as a cross check. As structure and dynamics are strictly related, it would be very interesting to study together with the vibrational states also the single particle dynamics of the proton in the attosecond scale. This would allow to determine the proton momentum distribution thus providing a new piece onf physical information for a thorough characterization of these materials. We propose a DINS experiment on VESUVIO at T=60,100,140,180 °C and p=1,2 bar.
DOI: 10.5286/isis.e.rb1620297
title: Probing possible p-wave superconductivity in Bi/Ni bilayers

description: Superconductivity and ferromagnetism are perhaps the best examples of how quantum mechanics can be employed to explain macroscopic phenomena. The two states, both containing coherent electrons, are traditionally considered antagonistic. Placing a ferromagnet in contact with a superconductor causes a suppression of the superconductivity. It is therefore a highly surprising result that placing very thin films of otherwise non-superconducting Bi next to ferromagnetic Ni, such that the two metals share an interface, causes the resulting heterostructure to superconduct with a critical temperature of about 4 K. It is possible that the superconducting mechanism responsible is the rare p-wave type. We plan to further investigate this highly unusual system using neutron reflectometry to extract the key length scales involved and probe the nature of the superconducting state.
DOI: 10.5286/isis.e.rb1620376
title: An assessment of the lattice strain in single phase High Entropy Alloys with large atomic size differences

description: High Entropy Alloys (HEAs) attract significant attention as a new class of materials that offer unique and attractive properties. It has been suggested that these multi component alloys necessarily contain high levels of strain in their structures, and this is often used to rationalise their properties. However, our recent total scattering study on the exemplar HEA CrMnFeCoNi has cast doubt on this assertion by demonstrating that the level of local strain in the HEA is comparable to that in compositionally simpler alloys. In the proposed experiment total scattering data will be used to probe the local structure of another exemplar HEA, VNbMoTaW, which exhibits much greater variation in atomic radii, to determine the extent to which its lattice can be considered strained. The results of this experiment could challenge one of the core principles on which the study of this field is based.
DOI: 10.5286/isis.e.rb1710178
title: Structure of antibiotic mixtures in lung surfactant membrane models at the air-water interface

description: Clarithromycin and Levofloxacin are essential antibiotics used to treat bacterial infections such as tuberculosis and pneumonia. Lung surfactants may be used as drug carrier of antibiotics directly into the airways. The phospholipid DPPC is a major lipid in commercial lung surfactants and is used to mimic their surface and mechanical properties so that it is a reasonable model. This proposal intends to investigate the structure of DPPC-antibiotics mixed monolayers in order to understand if they are suitable to be used as drug delivery systems in respiratory medicine. The idea is to use neutron reflectometry (NR) to characterize the density, packing, thickness, surface activity, and molecular area of the film at the air-water interface. Also, NR is a suitable technique for the study of interfacial structure, molecular organization and composition of mixed films.
DOI: 10.5286/isis.e.rb1710214
title: Solvent Segregation in Phase-Separated Li-NH3-MeNH2

description: We request 2 days on MAPS (or 3 days on MARI) to determine the extent of solvent segregation in a liquid-liquid phase-separated metal-amine: The Li-NH3-MeNH2 system. Recently we have demonstrated the homogeneity and liquid structure of the concentrated system, and determined the existence of liquid-liquid phase-separation across a large range of lower concentrations. The differing natures of the two liquid phases, and the strict restrictions on sample environment for the liquid, renders conventional techniques for chemical composition extremely complex (and indeed currently impossible in most cases). Neutron scattering techniques, however, have proven to be extremely well suited to metal-amine studies and will enable us to determine the composition and perhaps manner in which multiple solvents segregate between two very different coexistent phases that arise from a multi-component liquid
DOI: 10.5286/isis.e.rb1720248
title: Antibiotic binding to a bacterial outer membrane model containing oriented proteins and LPS on a contrasting deuterated thioalkane monolayer

description: The Outer Membranes (OM) is a feature of many pathogenic bacteria. It is  important as a barrier to antibiotics & the site of human-bacteria interaction. However bacteria are too small to allow us to do precise measurements of the structure and dynamics of this critical interface. Using neutrons as our eyes we have recently investigated OM models which imitate many aspects of the natural OM. Obtaining a dense protein containing version of the OM model has its own challenges and we have been developing a system where OmpF protein is assembled on gold surfaces so that it is 100% oriented .The spaces between are filled with deuterated decane thiol  and LPS on the outer surface. Here we want to extend our study of the important antibiotic PMB. Previous work at ISIS clarified the interaction with lipids and now we wish to understand how proteins alter PMB's mode of action.
DOI: 10.5286/isis.e.rb1720346
title: Investigation for large magnetic field enhancement of pressure induced-ferroelectric polarization in multiferroic DyMnO3

description: We propose to perform neutron diffraction experiments under high-pressure and magnetic field condition for multiferroic DyMnO3, using WISH beamline in combination with hybrid-anvil-type high-pressure device. From our recent high-pressure neutron work on the similar compound TbMnO3, we concluded that the giant ferroelectric polarization is caused by E-type magnetic ordering for Mn-spins. (N. Terada et. al, PRB 93 081104(R) (2016)) However, magnetic field-induced polarization enhancement in high pressure phase with significantly large change (0.7 μC/cm2) is still unclear. In this study, we are going to investigate how the magnetic orderings of both Mn and Dy spins are changed by magnetic field under hydrostatic pressure up to 6 GPa, using the hybrid-anvil-type high pressure cell.
DOI: 10.5286/isis.e.rb1800099
title: Polymorphism across the Na0.5Bi0.5TiO3-NaNbO3 solid solution

description: Na0.5Bi0.5TiO3 (NBT) based materials can present high level of oxide-ion conduction and therefore they are promising electrolytes for IT-SOFCs. The conductivity of highly conductive compositions of NBT materials present a change in activation energy around 325C, which falls in the temperature range where two polymorphs (R3c and P4bm) coexist. Here we request to collect neutron diffraction (ND) data on two compositions of a NBT based solid solution. The key objectives are 1) to determine the variation in the relative amounts of two polymorphs across the solid solution; and 2) to establish the possible relationship between conductivity and polymorphs of NBT materials and to further understand the oxide-ion conduction mechanism in NBT-based materials.
DOI: 10.5286/isis.e.rb1810068
title: Crystal and magnetic structures of polar Co2ScSbO6 oxides

description: Polar A2BSbO6 oxides with the Ni3TeO6 structure type (space group R3) are being investigated as possible ferroelectrics. Ni2ScSbO6 is reported to have incommensurate helical spin ordering with wavevector k = (0, 0.036, 0) below  60 K. We have prepared a new analogue Co2ScSbO6. Preliminary WISH data from a large sample made at ambient pressure, which contains ~35% Co2.5Sc0.5O4 impurity, show that Co2ScSbO6 has a long range ordering transition near 60 K, with a complex incommensurate spin order that is probably similar to that of Ni2ScSbO6. However, the high levels of Co2.5Sc0.5O4, and other unidentified impurities preclude accurate magnetic structure refinement. Hence we request time to collect data from a small high-purity sample of Co2ScSbO6 made at high pressure in order to be able to refine (and publish) the magnetic and crystal structures. We request 1 day for WISH beamtime.
DOI: 10.5286/isis.e.rb1810154
title: Aggregation and miscibility of dimethylcarbonate in hydrocarbon fuel model

description: Green Lizard Technologies are undertaking performance trials with dimethylcarbonate as a blend component in diesel fuels to reduce carbon particulate emission. Here, dimethylcarbonate/n-hexane mixtures, as a model system for new fuel blends, will be investigated to gain a more detailed understanding of the liquid structure and interactions providing a foundation to deliver a clearer understanding of these commercially important fuel additives.
DOI: 10.5286/isis.e.rb1810360
title: Operando Analysis of Lithium/Sulfur Cells with SANS and deuterated solvents

description: Lithium sulfur (Li/S) batteries have a fivefold higher theoretical gravimetric energy density (2680 Wh/kgsulfur) than state-of-the-art lithium ion batteries. However, the strong fading of electrochemical storage capacity with increasing cycle number is still a major obstacle to a broad technical use despite decades of research. For a holistic view on all pertinent length scales it is important to investigate the precipitation of both solid end phases, sulfur (S8) and lithium sulfide (Li2S) on the microscopic length scale. We want to correlate the SANS results with measurements of the electrochemical impedance spectroscopy (EIS), Bragg peaks and the capacity fading curve obtained. This unique combination of measurements will give valuable information about the charge and discharge processes and the capacity fading in Li/S batteries.
DOI: 10.5286/isis.e.rb1810637
title: A powder neutron diffraction study of the noncentrosymmetric superconductors Re6Zr, Re6Hf, and Re3Ta.

description: Noncentrosymmetric (NCS) materials have attracted attention because of their broken inversion symmetry, leading to unconventional superconducting properties including spin singlet-triplet mixing and time-reversal-symmetry breaking. The compounds Re6Zr, Re6Hf, and Re3Ta are all NCS superconductors. Powder x-ray diffraction data collected on these materials indicate that the samples all form as a single phase, but the refined compositions are non-stoichiometric. There is interest in performing precise density functional theory calculations to determine the band structure of these materials, and group theory analysis of the superconducting states of these NCS systems. This theoretical work requires knowledge of the position of the atoms, site occupancies and vacancies within the structure of these compounds. We propose to measure the crystal structure using powder neutron diffraction.
DOI: 10.14278/rodare.121
title: Kuramoto Model on KKI18 connectome

description: Results of fourth-order Runge--Kutta integration of the first-order Kuramoto model in brain connectome graph.


	Awr.dat.gz : connectome graph
	Awri.dat.gz : connectome graph with inhibitory links
	ccdata.tgz : simulations data for different configurations<br>
	(averages at top-level, single runs in folders)
	
		eERll*.dat: cube graph with random long-range links
		o.ocp-kur_{lambda}_*.dat: connectome with coupling lambda
		o.ocp-kur_{lambda}I_*.dat: connectome with inhibitory links, coupling lambda
		elo-Thr: smoothed probability distributions of avalance times
description: {"references": ["Gastner MT and \u0301Odor G. The topology of large Open Connectome networks forthe human brain. Sci. Rep.6, (2016) 27249"]}
DOI: 10.5286/isis.e.rb1520191
title: NR study of binding of short antimicrobial alpha-helix peptides with model lipid monolayer at the air/water interface

description: In this work we explore how our rationally designed peptide amphiphiles bind onto lipid monolayers using neutron reflection combined with deuterium labelling to the lipids, peptides and water. In the home work so far, we have developed lipid monolayer models mimicking mammalian and bacteria (G-, G+) outer cell membranes. To start this part of study, we propose to study how the G4 peptide bind to single and binary component monolayer models to understand how charges and saturation and membrane composition affect the amount of peptide binding and the extent of insertion. The careful use of isotopic contrasts will allow us to analyse the structures using the kenematic approach. 5 days of Surf beam time is requested to complete the tasks as proposed. This work will provide direct molecular insight of peptide selectivity to different membranes.
DOI: 10.5286/isis.e.rb1600024
title: Dynamics of the myoglobin-trehalose-water system for the understanding of cryopreservation
DOI: 10.5286/isis.e.rb1610077
title: Mass-selective neutron spectroscopy of Zr-Be amorphous alloy.

description: Neutron Compton scattering experiments will be performed for the first time on amorphous metallic system. Obtained results for Zr50Be50 system will be compared with existing inelastic neutron scattering data and computer simulation. Our estimation, using currently available simulated atom-projected vibrational densities of states, demonstrate sufficient mass selectivity for studies of nuclear-momentum distributions of beryllium and zirconium using forward and backscattering geometries. Measurements at different temperature (10, 200 and 300 K) will permit us to clarify the role of anharmonicity in the dynamics of metallic glasses.  In results we will obtain a much deeper insight into the interatomic bonding interaction and atomic dynamics in the metallic disordered systems.
DOI: 10.5286/isis.e.rb1610157
title: Vibrational Spectroscopy Studies of Porous Materials for High Capacity Ammonia Storage

description: The development of new porous metal-organic frameworks (MOFs) is receiving considerable attention worldwide owing to their potential for gas storage, separation, and purification. We seek to develop highly robust ammonia storage systems for portable applications and request 5 days on TOSCA to study the binding interaction between adsorbed ammonia molecules (NH3) and a robust porous MOF material [NOTT-300(Al)] as a function of NH3 loading. This proposed study will investigate the vibrational properties exhibited by both adsorbed gas substrates and the porous hosts. NOTT-300-Al exhibit high storage capacity for ammonia at ambient conditions (10.2 mmol/g) and more importantly fully reversible uptake, suggesting the presence of specific guest-host interaction. The proposed study aims to reveal the nature of the ammonia uptakes by analysing their vibrational/rotational spectra.
DOI: 10.5286/isis.e.rb1610256
title: Quantum-Critical Dynamics of a 3-dimensional Antiferromagnet

description: We have recently discovered a pressure-induced quantum phase transition (QPT) at 4.3 kbar in the gapped quantum magnet piperazinium hexachlorodicuprate (PHCC) by means of muon-spin rotation and inelastic neutron scattering (INS) measurements. The Heisenberg nature of the spins and the 3-dimensional spin network of PHCC allows, for the first time, the study of SO(3) symmetry breaking right at the upper critical dimension. This transition is of particular interest due to the presence of a Higgs (amplitude) mode. Previous INS experiments deep in the ordered phase have allowed us to identify the ordering wave vector. Here, we propose to measure the temperature dependence of the dynamic structure factor around the ordering vector at the QCP to study the universal scaling behavior and to reveal the special role of the upper critical dimension.
DOI: 10.5286/isis.e.rb1620233
title: Magnon-phonon coupling in magnetoelectric HoMnO3

description: The manipulation of magnetic properties electronically is of great importance in modern computing. Current  technology uses electric currents which draws a relatively large amount of power. An alternative scheme uses electric fields to control the magnetic properties via the magnetoelectric effect and this could reduce energy dissipation by as much as a factor of 100. One promising material is HoMnO3. Here, an applied electric field distorts the crystal structure, changing the magnetic interactions and consequently the magnetic state. To understand these properties and design materials with improved performance it is necessary to understand thecoupling between them. We aim to measure the magnetic and structural excitations in HoMnO3 and by combining this with careful modelling understand this coupling with implications for the design of future materials.
DOI: 10.5286/isis.e.rb1669003
title: Polymer Chain exchange mechanism of complex coacervate core micelles (C3Ms) - Anionic homopolymer

description: Complex coacervates have been studied for a long time for their medical applications and unusualphysical-chemical properties: they are dense networks of poly-electrolytes, that dissolve instead offlocculating when exposed to high salt concentrations. Despite being dense, they are fullypermeable to water, yet they are capable of strongly binding heavy metal ions or large (bio-)molecules, making them useful as drug carriers. By modifying them to form micelles, the micellecores become small coacervate networks; Complex Coacervate Core Micelles (C3Ms). Unlikegels, they are dispersed into solution easily and have an enormous active surface area. The formand structure of C3Ms are quite well known, but the exchange mechanism of polymers betweenmicelles is unknown. By performing contrast decay time-resolved SANS, we will determine ifpolymers migrate separately or not.
DOI: 10.5286/isis.e.rb1710351
title: Surfactant mixtures including a newly designed N-oxide

description: The applications of surfactant formulations based on N,N dimethylalkylamine oxides (AO) are dramatically increasing. The most widely used AO is the N,N-dimethyldodecyl-1-amine oxide (DMDNO). The phase diagram of DMDNO, shows an extended stability region of the micellar phase. However, lyotropic liquid crystalline phases, such as the hexagonal and lamellar ones, form above 40wt% DMDNO. For the production and application of surfactant formulations, liquid crystalline phases are disliked because of flowability and dissolution problems. To extend the stability region the micellar isotropic phase, a new N-oxide has been designed and synthesized, presenting a branched molecular architecture. Preliminary investigations have confirmed that this surfactant presents a scarce tendency to form liquid crystalline phases. However, its aggregation behavior in aqueous solutions is still unknown.
DOI: 10.5286/isis.e.rb1710361
title: One Dimensional Metal Chains on a Frustrated Triangular Lattice.

description: Nature abhors disorder and degeneracy at low temperature. Designing materials that confront this requirement can therefore lead to new states in which the degeneracy is lifted. Geometric magnetic frustration provides a means of creating the initial degeneracy when equal interactions from different atomic neighbours try to align moments in opposite directions. In our work this competition acts on chains of moments rather than single atoms. We have found a novel modulation along the chains, incommensurate with the crystal lattice, in which the magnitude of the ordered moments (rather than direction) is modulated.  Although part of the degeneracy is removed the magnetic structure still contains zero and reduced value moments, even at mK temperatures, manifesting a linear electrical resistivity to 350 mK. The proposal is to look at the excitations present to build a better understanding.
DOI: 10.5286/isis.e.rb1710372
title: Unveiling the exotic quantum critical point in CeCu6-xAgx

description: The heavy fermion system CeCu6-xAux is arguably the most important (and studied) heavy fermion series which exhibits a quantum critical point.  In recent years several new theoretical models have been proposed to describe the quantum critical behavior.   Consequently measurements using modern chopper spectrometers such as LET that can view the fluctuations throughout an entire Brillouin zone are crucial for resolving this theoretical debate.  We propose inelastic neutron scattering experiments using LET on a single crystal of CeCu5.5Ag0.5 to measure the fluctuation spectrum as a function of magnetic field and temperature. For these studies we request 7 days of beam time.
DOI: 10.5286/isis.e.rb1720028
title: Exploring Structural and Spin Orders in the Quantum Spin Liquid Candidate ZnxCu4-x(OD)6FBr by Powder Neutron Diffraction

description: Quantum spin liquids (QSLs) are intriguing states of matter in which magnetic frustration and strong quantum fluctuations prevent classical long-range magnetic order. To date, one of the best experimental realisations of such a system is herbertsmithite, ZnCu3(OH)6Cl2, but the exact nature of its QSL state remains a matter of debate. Here, we propose to explore Zn-doped deuterated barlowite, ZnxCu4-x(OD)6FBr, by powder neutron diffraction (PND). Like herbertsmithite, barlowite contains frustrated kagome layers of Cu2+ ions. The x = 0 member of the series undergoes a magnetic ordering transition at T ~ 15 K, but the effects of doping the system with non-magnetic Zn2+ ions are yet to be fully explored. PND is necessary in order to elucidate the nature of the spin order in barlowite below 15 K as well as determining the degree of Zn/Cu (dis)order.