cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1610061
title: Charged surfactant adsorption and detergency upon reconstituted plant cuticular wax films: A neutron reflection study

description: A number of studies have determined that non-ionic surfactants are capable of altering diffusionrates and transportation of both water and active ingredients thorough the waxy barrier of variouscrops, manipulating their morphology and structural integrity; however past investigations into the bulk composition of cuticular waxes suggest that charged and zwitterionic surfactants have a minimal effect upon the transportation properties of waxes.Our investigations into the influence of charged surfactants upon ultra-thin nano-films of reconstituted waxes - representative of waxes found upon the surfaces of crops - suggest that these surfactants do have a significant influence upon wax structure and integrity. A neutron study into the interaction of charged surfactants with waxes will allow us understand how surfactants promote the transport of water and active ingredients into crops.
DOI: 10.5286/isis.e.rb1610155
title: Metallic chains on a triangular lattice

description: Both 1D physics (dimensional frustration) and geometric frustration offer ways of achieving unusual quantum ground states that defy the usual tendency for systems to order at low temperature. The third law of thermodynamics however imposes that the system must find a single ground state.  Real materials often wriggle out of facing this dilemma. 1D materials may undergo a type of distortion known as a Peierls transition due to an interaction with the lattice, while long range interactions may circumvent geometric frustration. In this experiment we will determine the magnetic structure of a material that has both sources of frustration, each acting to eliminate the wriggle room of the other. A truly frustrated ground state could have quantum correlations that extend over long distances that are useful for making novel quantum devices.
DOI: 10.5286/isis.e.rb1610200
title: Probing the meta-stable nature and time induced ferromagnetic phase growth in Nd5Ge3: Neutron diffraction study

description: In recent years, the investigation of metamagnetic properties of first order magnetic systems has become revolutionary. The rare-earth based compound Nd5Ge3 exhibits a magnetic field-induced irreversibility and two metamagnetic transitions that are in first order transition by character. Mainly, the time induced growth of magnetic phase is puzzling. Towards this, the analysis of neutron diffraction as well as the time of flight measurements may throw light to unravel the underlying phenomenon.
DOI: 10.5286/isis.e.rb1610356
title: Verification of extended inverse Dzyloshinskii-Moriya mechanism by comparison of rhombohedral and hexagonal AgFeO2 polytypes

description: We propose to perform neutron diffraction experiments on single crystals, 3R-AgFeO2 and 2H-AgFeO2 on WISH. Recently, we have studied magnetic orderings and ferroelectricity of the polytypes with powder samples. [N. Terada et. al, PRL 109 097203 (2012), and PRB 91 094434 (2015)] These studies demonstrated that a contribution, p∝Si X Sj, plays important role for understanding appearance of ferroelectric polarization, which is added to conventional inverse Dzyloshinskii-Moriya (DM) term p∝eij X (Si X Sj), in cases of special symmetry conditions. These polytypes give a good opportunity to study the extended inverse-DM effect due to different parent space group (R-3m (3R) and P63/mmc (2H)). In this study, we would like to perform the detail magnetic structural determinations by using 3R and 2H-AgFeO2 single crystals, in order to verify the extended inverse-DM mechanism.
DOI: 10.5286/isis.e.rb1610357
title: Magnetic ordering in new multi-anion solids: Sr2Fe3Se2O3 and Sr2Cr3As2O2

description: We have identified new multi-anion solids with transition metals in unusual coordination environments and with apparently complex magnetic ordering. This experiment proposed for WISH will measure the thermal evolution of the magnetic scattering in two compounds with different crystal structures: Sr2Fe3Se2O3 contains Fe2+ ions in two different distorted octahedral environments and Sr2Cr3As2O2 contains Cr2+ ions in both square planar (by oxide) and tetrahedral (by As) coordination environments.
DOI: 10.5286/isis.e.rb1610395
title: A structural study of the unusual high-pressure magnetic  and superconducting phase of  FeSe

description: FeSe is structurally the simplest iron-based superconductor but one of the most intriguing electronically, with extreme tunability in its electronic and superconducting properties. With a superconducting transition of Tc~9K, FeSe undergoes a structural transition at Ts~87K but does not order magnetically at any temperature.  Furthermore, it shows a strong increase in its superconductivity from 8.7K to 37K under pressure,  which occurs in the presence of a new unknown magnetic phase. Our proposal is to understand the origin of the enhanced superconducting phase of FeSe by investigating the origin of the structural and magnetic phase in high quality single crystals of FeSe under pressure.
DOI: 10.5286/isis.e.rb1610429
title: Magnetic Structures of Ni2+ (S = 1) quasi-2D antiferromagnets

description: Our objective is to determine the magnetic ground state of two isostructural magnetic materials. Both contain nickel(II) ions in octahedral environments, NiX2N4 (where X = Br or Cl), and each material consists of S = 1 nickel(II) ions connected with pyrazine molecules to form a square lattice.By considering the powder neutron diffraction pattern above an below the ordering temperatures, we aim to determine the ordered moment size and direction in each compound. Through this, we can further our understanding of how the local nickel(II) environments affects the bulk magnetic properties of the systems.
DOI: 10.5286/isis.e.rb1610457
title: Location of the lipophilic drug testosterone propionate at the oil-water interface

description: Solubilisation of poorly-water soluble drug in surfactant micelles is an attractive means of increasing the apparent aqueous solubility of such drugs in order to administer the drug. Surprisingly little is known, however, about the relationship between surfactant and drug structure and the ability of the micelle to solubilise drug. As a drugs distribution in a surfactant monolayer is related to its distribution in the corresponding micelles, the present study aims to investigate the location of testosterone propionate (TP) in an SDS monolayer at the oil-water interface using neutron reflectometry in combination with contrast variation. The data thus obtained will be compared with the corresponding data we recently obtained at the simpler air-water interface. The study will provide invaluable information of the location of TP in SDS micelles.
DOI: 10.5286/isis.e.rb1810718
title: Spin Dynamics in a Quantum Pyrochlore Antiferromagnet

description: Frustrated compounds belonging to the pyrochlore family have attracted significant interest as they can host a huge variety of exotic phases. In order to explore the rich phase diagram of these 3D frustrated systems, one need to slightly vary the delicate balance between exchange, dipolar and spin-orbit interactions, for which a better understanding could lead to the stabilization of new quantum phases. Here, we propose to focus on the recently synthesized Sm2Zr2O7, whose ground state is still unknown. Sm2Zr2O7 has the necessary ingredients to host an exotic quantum spin liquid state in three dimensions.
DOI: 10.5286/isis.e.rb1810773
title: INELASTIC NEUTRON SCATTERING STUDY OF THE CRYSTALLINE ELECTRIC FIELD  OF CeNi9GeGa3 AND CeNi9Ga4

description: A current hot topic in correlated electron physics is the magnetic phase diagram resulting from competing Kondo and RKKY interactions with magnetic frustration. One interesting system in this context may be CeNi9Ga4 and solid solutions CeNi9Ge4-xGax which crystallize in a tetragonal structure. CeNi9Ge4 was found to be near a heavy fermion quantum critical point, showing a paramagnetic ground state with a huge Sommerfeld coefficient, exceeding 5.5 J/molK² . The latter appears being stabilized by its quasi-quartet crystal field (CEF) ground state degeneracy. In the solid solution series CeNi9Ge4-xGax we observe a pronounced weakening of the Kondo interaction and the appearance of long range magnetic order with a maximum TN ~2.8 K for CeNi9Ge3Ga. We proposed here to investigate crystal field excitations in this system in order to understand the complex magnetic ground state.
DOI: 10.5286/isis.e.rb1820482
title: Magnetic structure of CeRh6Ge4 from neutron diffraction

description: In Ce-based heavy fermion materials, there is competition between the interactions which lead to a magnetically ordered arrangement of the Ce magnetic moments, and the hybridization between the local moments and conduction electrons, which quenches the local moments. Sometimes the magnetic transition can be tuned to zero temperature at a quantum critical point (QCP), where unusual properties arise due to quantum fluctuations. CeRh6Ge4 orders magnetically at a low temperature of 2.5 K and the system can be readily tuned to a QCP, but CeRh6Ge4 has also been reported to be a ferromagnet, making a QCP highly unusual.  Therefore we propose to use low temperature neutron diffraction to determine the magnetic structure, in particular to see whether the system is purely ferromagnetic, or if there is a more complex arrangement of spins, allowing for the quantum criticality to be characterized.
DOI: 10.25345/c5k34b
title: MassIVE MSV000083661 - GImap_negative_C8_7.5mint_chaoyi
title: apply C8 column and 7.5 minutes run to feces, small intestine and large intestine samples from mice under negative polarity mode in ddMS2.
DOI: 10.5286/isis.e.rb1510474
title: Investigating the role of oxygen in the mechanism for the transformation from delafossite to spinel in CuFe1-xCrxO2

description: Materials for Solid Oxide Fuel Cells (SOFCs) are being developed continuously. Cuprous delafossites (CuBO2 where B=Cu, Cr) are being developed for cathode side applications in SOFCs, due to their semiconducting properties. CuFeO2 transforms from delafossite to spinel in an oxidising atmosphere at high temperatures, while CuCrO2 is stable. Solid solution compositions between these two parents also experience the transition. Data on four samples will be collected: CuFe1-xCrxO2 (x=0, 0.25, 0.5 and 1). Study of the role of oxygen in the mechanism of the delafossite-spinel transition is important ¿ the identification of intermediate phases, oxygen incorporation and transport in the structure will clarify the structure-property relationships of these systems, and the mechanism through which the delafossite-spinel transition occurs. This is important for further material development.
DOI: 10.5286/isis.e.rb1520031
title: muSR of Polyethylene Oxide: A Simple Proton-Conducting Polymer

description: Proton-conducting polymer membranes have significant technological applications in hydrogen or methanol fuel cells. muSR can shed light on the mechanisms for proton transport in polymers as Mu+ can be considered a mimic of the proton. We propose to use zero-field-muSR and weak transverse-field-muSR to measure Mu+ hopping rates in dehydrated polyethylene oxide (PEO) both above and below the glass transition temperature (Tg ~215 K). We will determine the Mu+ (and by analogy H+) hopping parameters (activation energies, pre-exponential factors) in PEO from the temperature dependence of the spin relaxation rates. In future work we will investigate how hydration and the addition of strong acids affect the hopping process, which will provide information useful for the optimization of proton-conducting membranes.
DOI: 10.5286/isis.e.rb1520072
title: Study of magnetic order in the Mott insulator BaFe2Se2O by muSR

description: We propose to carry out μSR measurements of the BaFe2Se2O Mott insulator material in order to understand the nature of its magnetic order. Magnetisation measurements on single crystals displays three AFM transitions (at 240 K, 115 K and 43 K). Heat capacity and Raman scattering measurements suggest in addition short-range magnetic order that survives up to high temperatures. μSR is an ideal tool to study this material, as with a single technique we will have access to information on both the short and long-range magnetic order in the material. In order to gain understanding on this properties, we propose to carry out muSR measurements (in zero applied field and in an small longitudinal field applied in the direction of polarisation of the muons) as a function of temperature between 400 K and 10 K.
DOI: 10.5286/isis.e.rb1520106
title: High resolution neutron diffraction study to investigate temperature dependent crystal structure of an antiferromagnetic PrFe2Al8

description: The crystal structure of the intermetallic PrFe2Al8 consists of a network of Al which forms quasi cage-like structure where the Pr and the Fe form chains of atoms along the c-axis. We propose neutron diffraction investigation of the nuclear and magnetic structures of PrFe2Al8 in order to understand the presence of ferromagnetic clusters of Fe, the metamagnetic transition in low fields and the antiferromagnetic order of Pr3+, which we have observed through macroscopic measurements. The structural peculiarities of the Al-network in PrFe2Al8 are understandably linked to its magnetism and hence, accurate estimates of bond distances and angles are essential to understand the formation of ferromagnetic clusters. The local symmetry of the Pr ion is an important parameter to be evaluated in order to estimate the crystal field levels using subsequent inelastic neutron experiments.
DOI: 10.5286/isis.e.rb1520120
title: Chain exchange mechanism of complex coacervate core micelles

description: Complex coacervates have been studied for a long time for their medical applications and unusual physical-chemical properties: they are dense networks of poly-electrolytes, that dissolve instead of flocculating when exposed to high salt concentrations. Despite being dense, they are fully permeable 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 micelle cores become small coacervate networks; Complex Coacervate Core Micelles (C3Ms). Unlike gels, they are dispersed into solution easily and have an enormous active surface area. The form and structure of C3Ms are quite well known, but the exchange mechanism of polymers between micelles is unknown. By performing contrast decay time-resolved SANS, we will determine if polymers migrate separately or in charge-neutral pairs.
DOI: 10.5286/isis.e.rb1520149
title: Quenched salt hydrates  new ways of probing water clusters.

description: Very rapid quenching of liquids to form a glass, from which crystalline phases are subsequently obtained by devitrification, is a powerful technique for obtaining novel metastable compounds and crystal structures. By chilling aqueous solutions with liquid nitrogen we have synthesized new salt hydrates that contain a variety of different water polymer structures. What is striking about these polymers is that they are all based on pentagonal ring motifs, potentially providing important information about the structure of water in supercooled liquids. Our first goal in this experiment is to determine the structure of three novel hydrates produced by the quench method, MgSO4.9H2O and two compounds of MgSeO4 and MgMoO4 of as-yet uncertain hydration state. Our second goal is to measure the thermal expansion of MgSeO4.9H2O and relate that to the crystal's water dodecamer.
DOI: 10.5286/isis.e.rb1520174
title: Two-Dimensional Triangular Mott Insulator

description: The 1T polytype of the transition-metal dichalchogenide TaS2 is a system with a very rich phase diagram. Upon cooling down, the crystal goes through a series of charge density wave phase transitions till reaching the commensurate phase. The 1T-TaS2 at the commensurate phase is regarded as a realization of a half-filled 2D Mott insulator. In a Mott state one expects the spins of the localized electrons to order in an antiferromagnetic manner. We would like to test this prediction using muon spin relaxation.
DOI: 10.5286/isis.e.rb1520195
title: Li-ion diffusion in the solid electrolyte LLT

description: The high voltage and energy density has made lithium-ion batteries ubiquitous in portable electronics, such as iPods, laptops and mobile phones. At present, they are typically composed of lithium cobaltate as a cathode, lithium ion-conducting organic polymer as an electrolyte, and lithium metal or graphite as an anode. A major concern is the safety aspect of liquid and common polymeric electrolytes. Liquid-free batteries show some advantages over the currently commercialized ones, including thermal stability, absence of leakage and pollution, resistance to shocks and vibrations, large electrochemical windows of application, and potential to incorporate in microelectronic circuits. Lithium lanthanum titanate is currently the best solid state electrolyte. We propose to test a series of theoretical predictions on the diffusion mechanism via quasi-elastic neutron scattering.
DOI: 10.5286/isis.e.rb1520212
title: Investigating competitive diffusion of methanol, dimethyl ether and water in a microporous catalyst

description: The competitive diffusion of components of the zeolite catalysed methanol to dimethyl ether (DME) process will be investigated using quasi-elastic neutron scattering. The diffusion coefficient of DME will be measured in a commercial sample of zeolite HY at temperatures between 300-400 K in the presence of D2O (the by-product) and CD3OD, methanol will also be measured in the presence of deuterated DME and D2O to understand the difference in diffusivity of the reactant and product mid-reaction. Measurements will also be taken of DME with D2O to investigate the diffusion behaviour upon reaction completion, and the diffusion of DME will be measured without D2O to understand the effect of by-product absence on diffusion.  Results will be combined with measurements of pure methanol in the same zeolite sample completing the first neutron study of competitive diffusion in a catalytic process.
DOI: 10.5286/isis.e.rb1520407
title: Search for new hydrogen, helium and neon hydrates at high pressure

description: This proposal is for time to search for predicted gas hydrates at high pressure. The results will provide insight into the factors governing the stability of the H-bonded networks of these hydrates and will underpin calculations.
DOI: 10.5286/isis.e.rb1520460
title: Low Temperature Magnetic Behaviour of Sm2Zr2O7

description: Pyrochlore oxides of the type A2B2O7 (where A = trivalent rare earth, B = tetravalent transition metal element) can form geometrically frustrated magnets displaying a range of interesting phenomena including spin ice, spin glass, and spin liquid phases. One exciting avenue of research in this field has focused on systems where, due to a smaller magnetic moment on the trivalent rare earth A-site, quantum fluctuations play an important role in controlling the low temperature physics of the materials. Recent studies have pointed to the possibility of quantum spin liquid behaviour (in which spin ice correlations exist at finite temperature, together with strong quantum effects), in a number of pyrochlore materials including Tb2Ti2O7 and Yb2 Ti2O7.
DOI: 10.5286/isis.e.rb1610177
title: Magnetic relaxation processes in tetragonal lanthanide single-molecule magnets

description: Single-Molecule Magnets (SMMs) are molecules that display slow relaxation of their magnetisation. We have designed a new class of mononuclear lanthanide SMMs, where the lanthanide ion is situated in a perfectly tetragonal crystal field. Depending on the lanthanide ion we have observed different magnetic relaxation processes, as probed by magnetic ac susceptibility. Here we intend to study two closely related holmium based systems, the only difference between the two being a change in point group symmetry at the lanthanide site. The low lying crystal field states measured with neutron spectroscopy and the lack of out-of-phase component in the magnetic ac susceptibility hints that the relaxation in these systems are so fast that muSR will be the ideal way to study the magnetic relaxation as a function of field and temperature in order to determine the nature of the relaxation processes.
DOI: 10.5286/isis.e.rb1610351
title: Structural Studies of Mixed Monolayers of Sulfobetaines with Phospholipids

description: Sulfobetaines are zwitterionic surfactants where the headgroup charges are arranged in the opposite manner to those found in phosphotidylcholine lipid headgroups. Sulfobetaines are relatively non-toxic and are being considered for drug delivery and biomaterials applications. We therefore wish to study the interactions between model lipid membranes of DMPC with insoluble sulfobetaines. We have measured X-ray reflectivity from these systems but require neutron reflectivity data with contrast variation to be able to gain information on the details of headgroup interactions in these systems. We have synthesised novel double-tail sulfobetaine surfactants, and their corresponding single tail versions in our lab, so have both deuterated and hydrogenated surfactants available. These NR measurements will enable publication of this work, and form an initial study in ongoing work.
DOI: 10.5286/isis.e.rb1610384
title: Muonium Charge-State Transition Energies in Si-Ge Alloys

description: We propose longitudinal muon spin depolarization measurements for two additional samples of Si(1-x)Ge(x) alloys in order to complete our study of the dependence of Mu(-/0) acceptor level energies on alloy composition and the T-site configuration.  A sample with x=0.87 will help better determine where the T(Si2Ge2) related level crosses the valence band edge, implying that a negatively charge Mu ion will serve as the core for a shallow Mu acceptor state. We have already shown that the acceptor levels for T(Ge4) and  T(Si1Ge3) are valence-band resonant above x=0.92 and x=0.80, respectively.  The current data suggest the the T(Si2Ge2) level enters the band near x=0.86, thus the level for x=0.87 should lie just below the band edge. A sample with x=0.55 is important for confirmation of data suggesting that an alloy bowing parameter is needed to slightly lower the mid-range band edge.
DOI: 10.5286/isis.e.rb1661006
title: Characterization of Indo-Persian axes in the Wallace Collection
DOI: 10.5286/isis.e.rb1810642
title: The effect of electrostatics on the spontaneous formation process of vesicles in surfactant mixtures

description: Spontaneous vesicle formation is observed in mixtures of anionic with cationic/zwitterionic surfactants and this process can be slowed down by addition of copolymer. Aim of the planned stopped-flow SANS experiments is to elucidate the effect of electrostatic interactions between the two surfactants, which for zwitterionic TDMAO can be tuned easily, as at lower pH it becomes protonated and thereby a cationic surfactant. By additional variation of ionic strength we will modify all relevant electrostatic parameters. Using a perfluorinated anionic surfactant we can address by contrast variation the question of how homogeneous the growing disks are. The experiments will lead to a much improved understanding of how electrostatic interactions affect this spontaneous process of vesicle formation, which is important for tailoring structure and properties of kinetically controlled vesicles.