cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1520164
title: Temperature Dependence Study of the Local Magnetic Behaviour in Fe3C-Filled Nanowires

description: Recent research in to Carbon Nanotubes filled with magnetic materials has produced some interesting results that have the potential to bring about new computing technology.  In particular one type of system referred to as a nanowire has shown particular promise. However, a deeper understanding of the fundamental magnetic properties is required to fully utilize these materials in novel applications.  For the first time new fabrication methods have made it possible to study these systems using the MuSR technique which can provide vital information about the origins and behavior of the magnetic properties that conventional techniques cannot.  Our key objectives in this proposal are to carry out the first MuSR studies, determine the origin of the magnetic properties and understand the role of the lattice crystal structure on these properties.
DOI: 10.5286/isis.e.rb1520262
title: Structural phase transition in SnSe with ultra low thermal conductivity

description: SnSe has recently been reported to have very good thermoelectric performance. This is linked to an ultralow thermal conductivity and occurs in the B-phase (ZT &gt; 2 above 800 K). We propose to investigate the structural phase transition from the A to B phase in detail, and to determine the temperature dependence of the thermal displacement parameters. This information will be linked to the observed ultralow thermal conductivities.
DOI: 10.5286/isis.e.rb1520339
title: Effects of IR Illumination on Mu Dynamics and Mu0 Formation in TiO2

description: We propose a study of Mu dynamics and the low temperature Mu$^0$-like states in TiO$_{2}$ under near-IR illumination to investigate the resulting excitonic states and behaviour. This proposed work will shed light on the role and effects that the hydrogen impurity plays in the significant conductivity enhancement under IR illumination as well as changes to the shallow donor state detected below 10K. These proposed measurements also provide a test of MuSR?s ability to function as an experimentally accessible analogue to the early time history of hydrogen impurities in an excited state.
DOI: 10.5286/isis.e.rb1520483
title: Muon Level Crossing Resonance Studies of Anion-exchange Membranes Under Different Humidities

description: Anion-exchange membranes are used in alkaline fuel cells, a technology which allows for the production of power from hydrogen in impure gas streams. Very little is known about the microscopic processes behind the anion (hydroxide) conduction in these membranes. Level crossing studies with muons will allow some investigation into the dynamics of the grafted polymer chains, which contain phenyl groups (which interact with muonium to form radicals). These studies will yield information about the changing polymer dynamics associated with different humidities (and therefore different anion conductivities).
DOI: 10.5286/isis.e.rb1569007
title: Effect of shear and adsorbing polymers on cellulose micro-fibrils
DOI: 10.5286/isis.e.rb1600004
title: Hydrogen loading and unloading kinetics in thin Mg films
DOI: 10.5286/isis.e.rb1620069
title: Surfactants in the mirror: aggregation of very low surface tension surfactants

description: The results from this experiment will develop alternatives to controlling surface tension through the design of 21st century surfactants (better performance at lower concentration with lower environmental consequences) by gaining essential information on how molecular structure affects aggregation. A sister proposal has been submitted this round to study adsorption of similar surfactants by neutron reflectivity (Take it to the limit: VERY low surface tension surfactants).
DOI: 10.5286/isis.e.rb1620093
title: Inelastic neutron scattering investigation of Sr2CuTeO6

description: Isostructural Sr2CuBO6, B=W or Te, exhibit different magnetic structures k=[0 1/2 1/2] vs [1/2 1/2 0], leading to the suggestion of a reversal in the ratios of the nearest and next nearest neighbour interactions, which is proposed to be due to the difference in the superexchange interactions mediated via the hexavalent B ion. Using INS we have identified that J2&gt;&gt;J1 for B=W, and now we wish to investigate the proposal that J1&gt;J2 for B=Te, before looking at the solid solutions between W and Te to explore the critical regime for J2/J1=1/2, which may host a quantum spin liquid.
DOI: 10.5286/isis.e.rb1620196
title: Inelastic Neutron Scattering Study on the Spin-Orbital Coupling in Fe1-xMnxV2O4

description: The vanadium oxide spinel AV2O4 has attracted a lot of attention due to the complicated interaction between charge, spin, orbital, and lattice, which could create the exotic states and lead to several intriguing phenomena, such as multiferroicity, and colossal magnetoresistance. If the A-site ion is Fe2+, both A-/B-site ions have the orbital effect and the multiferroicity, containing both ferroelectric and ferrimagnetic moments, is found at low temperatures. Hence, the material FeV2O4 has emerged as an important model system in both theoretical and experimental research. Moreover, the lower structure transition in Mn-doped FeV2O4 does not linear decrease: as x&gt;0.6, the transition temperature increases, which suggests a competition of the interactions and lattice existing in the system. Therefore, this work will help us understand the spin-orbital interaction in the frustrated system.
DOI: 10.5286/isis.e.rb1620253
title: Neutron reflectivity of water soluble conjugated polymer/surfactant films

description: Water-soluble conjugated polymers (WSCP) are an important class of materials which have received great attention as active materials in optoelectronic devices and in biosensing. The optoelectronic properties are directly related with their structural organization and therefore intra and/or interpolymeric pi-pi stacking affects the charge transport and energy transfer processes occurring in the devices. The characterization of luminescent films at the solid-liquid interface will be very important to establish a relationship between the photoluminescence properties and morphology of the materials. The NR data on a PEDOT:PSS(with ethyleno glycol, EG)-Si  substrate will allow us to mimic a sensor where EG-PEDOT:PSS works as an electrode, a polyfluorene  derivative bearing aza-crown pendent groups as an active layer, and sodium dodecyl sulfate surfactant as a model molecule for an analyte.
DOI: 10.5286/isis.e.rb1620382
title: Investigating the synthesis and decomposition of light mixed metal amides for ammonia decomposition applications

description: We request 3 days on POLARIS to perform in situ, combined powder diffraction-gravimetric analysis on the formation and decomposition of three mixed lithium-potassium amides.  Accessing the intrinsic hydrogen content within ammonia has the potential to play a significant role in sustainable energy storage applications. Inexpensive light-metal amides are among the most active ammonia decomposition catalysts and are likely to surpass the performance of transition metal based catalysts. Creating mixed metal amide systems is one way to tailor their function. The Li-K amide systems show great promise in this regard, promoting the decomposition of the system to the metal imide at significantly reduced temperatures. In situ diffraction data will help to unravel the complex decomposition mechanism observed in these species and thus inform the design of future metal amide and imide catalysts.
DOI: 10.5286/isis.e.rb1620396
title: Effect of high temperatures on the adsorption of benzotriazole onto copper/copper oxide surface from oil

description: Benzotriazole (BTAH) is a very effective corrosion inhibitor for copper and its alloys in both water and in oils. BTAH is introduced as a corrosion inhibitor in oil based systems over a broad temperature range starting from room temperature (lacquers and varnishes) to temperatures above 100 C (transformer ,engine oils).BTAH is strongly adsorbed onto copper surfaces and forms thick layers on the surface. It is now believed that this thick layer offers protection from corrosion by shielding the surface from corrosive species.The key objective of this proposal is to study how the structure of this passivating BTAH layer changes with temperature as any structural changes in the layer will significantly affect the corrosion inhibition efficiency of BTAH.
DOI: 10.5286/isis.e.rb1620467
title: Anomalous lattice dynamics of the elemental superconductor niobium

description: Phonon lifetimes in BCS superconductors provide information on the details of the electron-phonon coupling  mechanism. In 2008 high-resolution neutron inelastic scattering experiments revealed unexpected anomalies in the lifetimes of transverse acoustic modes in the elemental superconductors Pb and Nb. These experiments were performed using a resonant spin-echo technique. To date no quantitative explanation for these anomalies has been forthcoming. Here we propose to exploit the unprecedented high-resolution of LET to investigate phonon lifetimes effects arising from electron-phonon coupling in Nb. In addition to providing an important check of the surprising behaviour of the acoustic modes, our experiments will provide a high-resolution survey of the longitudinal acoustic modes where new features may be expected.
DOI: 10.5286/isis.e.rb1669000
title: VC-precipitation kinetics of C-Mn-V and C-Mn-V-Mo steels in austenite and ferrite phases

description: Nano-steels are a new generation of Advanced High Strength Steels, extremely suitable for lightweight automotive applications. The ferrite phase, which provides ductility and stretch, is significantly strengthened by nanometer-sized precipitates, which can increase the strength level by 30-50%. These steels contain different microalloying additions, such as vanadium (V) and molybdenum (Mo), which form the essential nano-precipitates. An efficient use of these additions requires further knowledge on the precipitation kinetics of the specific carbides and carbonitrides, and the interaction of these precipitates with the austenite to ferrite phase transformation. The work proposed here, which is part of a four-years project, aims to provide valuable quantitative data on the VC-precipitation kinetics in both austenite and ferrite and elucidate the effect of solute Mo and V additions.
DOI: 10.5286/isis.e.rb1520030
title: Vibrational property analysis of NdGaH1+x using inelastic neutron scattering

description: The proposed experiment at ISIS aims at the characterization of the vibrational properties of the novel hydrogenous Zintl phase NdGaH1+x by inelastic neutron scattering (INS). INS spectroscopy is especially sensitive to the vibrations of hydrogen atoms. It is hoped that INS spectra will give insight into the dynamic properties of H atoms in a peculiar structural feature, namely a disordered linear Ga-H chain, and provide understanding of its chemical bonding.
DOI: 10.5286/isis.e.rb1520087
title: ALCs investigation of the polymer PTAA (chain length = 80)

description: This proposal aims to study the avoided level crossing resonances (ALCs) of the amorphous polymer PTAA, with chain length 80. Previous measurements on PTAA have studied a bimodal sample containing two different length PTAA chains (n=10 and 80) and a monomdal sample (n=10). It was found that the ALCs width and amplitudes were different for the two samples, which was probably due to the distribution of local order within the PTAA. For this proposal we would like to study the ALCs of as a function of temperature of a monomodal n=80 PTAA sample, to complete the study and compare with the bimodal and monomodal data.
DOI: 10.5286/isis.e.rb1520254
title: Regeneration of ammonia borane using hydrazine and ammonia from polyborazylene and spent AB

description: Ammonia borane (AB) is a highly promising hydrogen storage material. Recently we have shown that combining AB with a polymer produces a material which has great potential for wide a range of commercial applications. In order to become a viable alternative to fossil fuels, it is important that effective recycling protocols are developed for the material. The most promising regeneration protocol reported to date involves treatment of polyborazylene (PB), which used as a surrogate for neat AB waste, with hydrazine in liquid ammonia. This process reportedly achieved almost quantitative yields of AB -up to 95%. We have attempted to replicate this procedure using real AB waste and have found that the protocol is much less effective. We hope to use neutron spectroscopy to gain an insight into the differences in the chemistry of PB and waste AB when treated under the regeneration conditions.
DOI: 10.5286/isis.e.rb1520265
title: Validating a new theoretical method for predicting the HFC of small molecular semiconductors

description: ALC is the best technique to characterize muoniated radicals, that are produced by muonium bonding to unsaturated bonds in molecules. Good agreement between data from ALC and theory to specify muon sites can justify and quantify the materials properties extracted from previously published and as-yet unpublished data, but to date DFT calculations have proven to make somewhat unreliable predictions. For example, DFT calculations for TIPS-Pentacene resulted in a predicted hyperfine constant which was 40% higher than the experimental results. We have recently used the implicit solvent approach, calculating over 100 different possible structures, to make a prediction which was just 5 G away from an experimentally found ALC. We now wish to finish validating this approach against all ALCs in the molecule, to demonstrate a definitive theoretical method for calculating hyperfine constants
DOI: 10.5286/isis.e.rb1520438
title: Study of a copper oxalate 1DHAF chain system

description: One dimensional Heisenberg antiferromagnetic  (1DHAF) chain systems continue to attract interest as there are several outstanding questions about the nature of the propagation of spin excitations, whether ballistic or diffusive and, if diffusive, what power law characterises the autocorrelation function. Systematic studies across a range of 1DHAF systems should help to understand these issues. Muon measurements are proposed here to study a copper oxalate 1DHAF system that is formed via Jahn-Teller distortion and orbital ordering of an underlying honeycomb lattice. Zero field studies will be used to search for magnetic ordering at low temperatures due to residual interchain interactions. These interactions may be suppressed by frustration leading to very low ordering temperature and thus a highly ideal 1DHAF. Field dependent studies in the 1DHAF phase will test the propagation mechanism.
DOI: 10.5286/isis.e.rb1520453
title: Surveying Hebel-Slichter peaks in conventional-ish superconductors

description: The presence of a Hebel-Slichter peak in NMR or µSR measurements just below the critical temperature of superconductors is taken to be strong evidence for conventional behaviour and its absence heralds unconventional physics. Making this measurement has been a mainstay of NMR studies of superconductors for more than 50 years, but even though muon measurements famously revealed this phenomenon in fulleride superconductors well before NMR was able to reproduce the finding, it has rarely been used otherwise. Here we propose to make a broad survey across superconductors known from NMR to display Hebel-Slichter peaks to see how best to measure the phenomenon with muons. This is likely to be exceedingly challenging technically but success could open up a new field of study for µSR.
DOI: 10.5286/isis.e.rb1520458
title: ALC studies of solid benzene

description: For muoniated radical spectroscopy studies, benzene has long been the classic prototype system.  However most of these studies have been at higher temperatures, often in the liquid phase, whereas calculations of hyperfine coupling are generally made at zero temperature, deep in the solid phase. It is therefore desirable to obtain reference ALC data for benzene extending to as low a temperature as possible, to allow accurate comparison to be made with DFT computations of the full hyperfine tensor including the effects of zero point motion. HiFi will be therefore be used to study the ALC spectrum of solid benzene over as wide a range of temperature as possible and spectral anomalies suggested by previous reports will also be investigated further, in particular a low temperature spectral feature that is suggested to be a signature of quantum diffusion of muonium round the ring.
DOI: 10.5286/isis.e.rb1520461
title: μSR Study of the B20 superconductor AuBe

description: In conventional superconductors inversion symmetry plays an important role in Cooper pair formation. The discovery of superconductors lacking inversion symmetry (non-centrosymmetric) has attracted considerable attention experimentally and theoretically [1-6]. Cooper pairs in conventional superconductors form from two electrons of opposite momentum in the same band at the Fermi energy. The lack of inversion symmetry results in the loss of spin degeneracy and the presence of more than one band at the Fermi surface. This may lead to unconventional superconductivity.
DOI: 10.5286/isis.e.rb1567486
title: Reinvestigation of muon sites in the high-Tc superconductor, YBa2Cu3O6
DOI: 10.5286/isis.e.rb1610024
title: Characterization of heterogeneous solvent structure in a carbon capture fluid

description: We propose to use neutron scattering experiments to gain molecular level insight into an intriguing liquid structure observed in a water-free CO2-capture solvent.  Switchable ionic liquids (SWILs) are a promising class of CO2-separating solvents that entail an intrinsic heterogeneous, micro-domain solvent structure that changes size, shape and orientation of both molecular and ionic domains as a function of CO2 loading.  We aim to study interesting chemistry and controlling principles to determine how these gradient changes in molecular structure impacts CO2 chemisorption and diffusion of CO2 to and from the liquid.
DOI: 10.5286/isis.e.rb1610206
title: Quasi-elastic neutron scattering using Neutron Spin echo

description: We propose a measurement of the effectiveness of using the RF flippers on Offspec in a quasi-elastic mode (theta=90°) with the RF at 0.5MHz. This is important to our future development of quasi-elastic scattering using neutron spin-echo on the new Larmor instrument as this experiment will guide our design. We will measure a resolution standard (carbon) and also a strong scatterer with dynamics in the available 5-10ns time window.
DOI: 10.5286/isis.e.rb1620043
title: Organogels with CO2-philic surfactants

description: SANS will be used to probe the internal structures of organogels consisting of custom synthesized CO2-philic surfactants and p-phenol low molecular weight organogelators (LMOGs, Figure 1). These LMOGs are commercially available and relatively low in cost, it is proposed that the internal structures of these thermoresponsive structures will be explored around the pronounced melting point (Figure 3), where a sharp decrease in viscosity is observed. The surfactants under study are partially fluorinated analogues of commercially available Na(AOT) (Figure 1,a-c), and interestingly, are seen as universal surfactants, due to their compatibility in water and oils, as well as in high pressure solvents such as supercritical CO2 (scCO2)1,2
DOI: 10.5286/isis.e.rb1620133
title: Investigating the diffusion component of the toluene hydrogenation reaction in Pt/MCM-41

description: The diffusion of hydrocarbons relevant to the toluene hydrogenation reaction will be measured both as unconfined liquids and confined in the catalyst Pt/MCM-41. Diffusion will be measured at a number of temperatures. This work is part of a larger project where the kinetics pf toluene hydrogenation has been succesfully measured using neutron total scattering. Analysis of the temporal changes within this system indicated that the liquid re-organisation inside the pores was the slowest step of the reaction. The acquisition of further information about the dynamics could provide guidance on future catalyst design and development. For this reason the diffusion of the species present during this reaction (namely toluene and methylcyclohexane) is of great interest.
DOI: 10.5286/isis.e.rb1620414
title: Gas condensation and fluid behaviour in nanoporous ZIF-8 materials upon gate opening structural transition.

description: This proposal aims to study condensation transitions in nanoporous flexible materials by means of wide Q-range neutron diffraction. We plan to perform an in-situ gas adsorption/desorption experiment on the zeolitic imidazole framework ZIF-8 and monitor the behaviour of the adsorbate upon condensation within the pores during the gate opening structural transition. This neutron study complements our X-ray absorption and X-ray emission spectroscopy work performed at the I20 beamline at Diamond. With this combined study we expect to provide improved understanding of the microscopic details of the host-guest interactions for ZIF materials that will be very valuable for a molecular understanding of the framework flexibility and the gate opening phenomena.
DOI: 10.5286/isis.e.rb1620434
title: Uniaxial pressure effect in FeTe

description: Superconductivity in iron-based materials occurs in close proximity to a long-range ordered magnetic phase. In the iron pnictides, uniaxial pressure shifts the magnetic ordering temperature and increases the size of the magnetic moment near optimal superconductivity, suggesting enhanced quantum fluctuations [Tam et al., submitted]. FeTe, the parent compound of the Fe(Se,Te) system, forms a unique double-stripe magnetic order that is incompatible with superconductivity, but at higher energies the spin waves merge into the same form observed in superconducting Fe(Se,Te). Here we propose to study the spin wave evolution under uniaxial pressure in order to determine the energy scale of these two competing instabilities. The additional detwinning effect of uniaxial pressure in the low-temperature phase will also establish the instrinsic spin-wave parameters for the first time in this system.
DOI: 10.5286/isis.e.rb1620500
title: DLS proposal number 14670 on I07
DOI: 10.5286/isis.e.rb1510336
title: Towards the development of carbonitrides as novel two-stage regenerable reagents for the production of nitrogen-containing organic molecules

description: We are examining a number of cobalt-molybdenum carbonitrides as possible catalysts for reactions that produce nitrogen-containing organic molecules. There is good evidence that these can cycle nitrogen from a gas stream into their crystal lattice and back again. This experiment investigates the formation and transformation of such carbonitrides under various gaseous environments to understand the conditions under which anions enter or leave the different lattice sites that they can occupy. The strong neutron scattering from carbon and nitrogen, with good contrast between them, makes neutron diffraction ideal for this purpose. The success of this experiment will allow us to predict conditions under which catalytic reactions are likely to occur most readily.
DOI: 10.5286/isis.e.rb1510338
title: Force transfer mapping in cemented granular materials under applied boundary loads

description: Understanding the micro-scale processes that act during the loading of cemented granular materials (e.g., sandstones) is yet to be achieved. Recent developments have proven that neutron diffraction scanning during in-situ loading tests can become an important tool to this end. This proposal is a continuation of RB1320418, in which a successful step was made regarding the investigation of the distribution evolution of forces/stresses that lead to sample failure. Through a new experimental approach using a prototype load cell, neutron diffraction mapping of the grain-strains of a sand sample was made. In this experiment the same technique will be used for cemented sand specimens to reveal the contribution of cementation in the overall strain distribution evolution.