cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1710179
title: The mobility of water in graphitic carbon nitrides

description: Carbon nitrides are emerging as an important class of materials with a variety of technical applications  The focus of this study are  polytriazine imide (PTI) materials, which are the only crystalline graphitic carbon nitrides that can be synthesised readily and reproducibly. These comprise a 2D network composed of planar layers with voids in these layers which form channels filled with Li+ and Cl- ions. A recent observation has been that the lithium and chlorinte can be removed from the PTI materials by washing with water. We can rversibly intercalate wate into these structures and the goal of this study is to establish the mobility of hydrogen within these modifoed and unmodified materials, both within channels formed by the triazine layers and between graphitic layers. Overall the the goal is to understand the influence of these guest atoms on the materials properties
DOI: 10.5286/isis.e.rb1710400
title: Spontaneous strain and framework distortion in hybrid Prussian blue analogues

description: The metal-organic Prussian blue analogues (HIm)2K[M(CN)6], where HIm is the imidazolium cation and M = Fe or Co, have switchable dielectric constants, since the imidazolium ions are free to rotate in their planes at high T but freeze into a single orientation at low T. Both materials exhibit an intermediate-T phase isosymmetric to the high-T phase; the nature of this phase is not obvious, but analysis of the spontaneous strain associated with both phase transitions suggests important differences between the Fe and Co compounds related to the differences in cation size. However, this analysis is based on few measurements of limited precision. We propose here an HRPD study in order to measure the spontaneous strain at many temperature points and to high precision, to resolve the differences between these materials and direct future work on electrically functional framework materials.
DOI: 10.5286/isis.e.rb1710447
title: Tracking setting dynamics of portland cement at reduced and elevated temperatures

description: Cements remain the most commonly used materials worldwide. Portland cement is the worlds most widely manufactured material, yet remains one of the most complex and least understood systems,particularly at the atomic level. Building upon our recent success with tracking setting dynamics of dental cement with VESUVIO, we look to further resolve NCS profiles in portland and novel geopolymer cements. Preliminary NCS measurements of portland cement at 300K shows similar oscilatory trend to the dental cement. To further resolve these trends we propose to track the setting at higher and lower temperatures to resolve its role on atomic-cohesion (bonding). Concurrent prompt gamma activation analyses (PGAA) and novel electrical measurements (of dopant ions) will provide complementary information, whilst helping evolve the scope of simultaneous techniques available on the VESUVIO experiment setup.
DOI: 10.5286/isis.e.rb1720141
title: Hydrogen diffusion at hight temperature and pressure  in palladium-silver membranes measured by QENS

description: Hydrogen selective membranes based on palladium are very important for technological processes such as isotopic separation and gas purification. As a matter of fact, both tensile strength and permeability show a maximum for a silver content in the range of 20-40 %wt., which exactly corresponds to commercial Pd-Ag alloy used for membrane applications (such as fuel cycle in fusion reactors). The structure of Pd-Ag membranes loaded with deuterium was investigated at ILL (D1B and D2B instruments), while the density of vibrational states projected on the proton was measured on MARI. QENS measurements were performed on OSIRIS in the range of p=1-2 bar and T=70-300 °C. We propose a QENS experiment to extend the p and T range up to 4 bar and T up to 400 °C to have a more complete picture of the microscopic diffusion process to be compared to the macroscopic one measurable in the ENEA laboratory.
DOI: 10.5286/isis.e.rb1720235
title: High energy spin fluctuations in YFe2Ge2

description: The newly discovered superconductor YFe2Ge2 (Tc about 1.8K) has the same crystal structure as 122 iron-based superconductors. While no static magnetic orders has been reported, our recent triple-axis experiment revealed strong spin fluctuations at Q=(1,0,1), corresponding to a stripe antiferromagnetic correlation consistent with in the 122 systems. Thus, there comes a contradiction between the similarity to 122 systems and the rather low Tc in YFe2Ge2. In order to have further understanding of the superconducting mechanism of this compound, we propose an experiment on the high energy spin fluctuations in YFe2Ge2, which will enable us to determine the effective Hamiltonian and to make a direct comparison with the 122 iron-based superconductors. Our experiment will shed some lights on the mechanism of pairing and the origin of low Tc. We request a 7 days' beam time for MERLIN.
DOI: 10.5286/isis.e.rb1720249
title: Crystal field and spin-wave excitations in the quasi-2D honeycomb zigzag antiferromagnet Na2Co2TeO6

description: The microscopic origin of the zigzag magnetic ground state in a honeycomb lattice of the quasi-2D antiferromagnet Na2Co2TeO6 is debatable. The zigzag phase may occur due to (i) the J1-J2-J3 Heisenberg models for a wide range of exchange parameters, (ii) hierarchy of exchange interactions between nearest neighbours due to orbital ordering, or (iii) presence of strongly anisotropic interactions in the proximity of the Kitaev spin liquid. We propose inelastic neutron scattering measurements on Na2Co2TeO6 using the Merlin spectrometer  to determine the origin of the zigzag ground state (out of the above three possibilities) as well as to explore the possible signature of quantum effects.
DOI: 10.5286/isis.e.rb1720262
title: Temperature dependence of phonon modes in  protonated (H2O) and deuterated (D2O) ice

description: Recentely we have measured (RB 1620263) pressure dependence of phonon modes in  both the protonated (H2O) and deuterated ice (D2O)  (Fig. 2) at ambient, 0.3  kbar, 1.0 kbar and 1.6 kbar at 225 K. The high pressure measurements  have enabled to experimentally determine the energy dependence of the Grüneisen parameter.  Further, the combination of temperature and pressure measurements would help to determine the implicit (function of unit cell volume) as well as explicit (function of thermal amplitude of atoms) anharmonicities.  The temperature dependent  measurements include both the effects, while the pressure dependence includes only the implicit contribution.  The pressure and temperature dependence of phonon data along with ab-initio phonon calculations would provide a quantitative framework to understand the anomalous phonon behaviour of these compounds.
DOI: 10.5286/isis.e.rb1720323
title: Probing possible Dirac magnons in collinear antiferromagnets

description: Topological state of matter remains one of the central topics in condensed matter physics since decades ago. Take graphene as an example, the electron bands are linear and touching with each other in the Brillouin zone. The dispersion near these touching points can be described by the Dirac equation, therefore the excited massless quasiparticles and these touching points are called Dirac electrons and Dirac points, respectively. Analogous to the linear band touching of electrons, recently a spin web compound Cu3TeO6 (CTO) has been proposed to support the Dirac magnon excitations near the linear band touching points of the optical magnon branches. Hence,  mapping out the spin excitation spectra in the bulk to check whether there are linear band touching points directly is critical to test the idea of the formation of Dirac magnon bands in CTO.
DOI: 10.5286/isis.e.rb1720393
title: In-situ QENS studies of the nitridation of Calcium Hydride

description: The proposed experiment will study how material properties change as a function nitridation (eg. the incorporation of nitrogen gas into the material). In previous study at RAL, we found that a pellet of CaH2 when exposed to nitrogen gas showed a dramatic increase in conductivity of hydride ions (H-). We will use quasi-elastic neutron spectroscopy to study how the local ionic motion of H- changes as a result of nitridation. This experiment will inform us about the kinetics of reversible hydrogen uptake and release with applications in hydrogen storage systems. Furthermore, the high conductivity of the material makes it applicable in next-gen fuel cell systems.
DOI: 10.5286/isis.e.rb1800015
title: Example SANS Data from Lactoferrin in Solution for use in a Methods Chapter on Neutron Scattering Techniques
DOI: 10.5286/isis.e.rb1800016
title: Neutron Reflectivity Study of Protein Adsorption onto Cell Membrane-inspired Anti-Fouling Phospholipid Polymer Brush Surface

description: We grafted 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer brush from the silicon wafer surface through Cu (0) mediated controlled radical polymerization (CuCRP) to mimic cell membrance. Excellent control over graft density and film thickness was acheived by reaction condition variation. An optimal thickness of PMPC for protein resistance was estabilished. The adsorption then was found to increase together with the PMPC thickness. This can be either attributed to an increased surface adsorption or to protein penetration within the structure.In order to progress our understanding of the system further, we need to determine the protein distribution across the PMPC layer as a function of both protein concentration and graft density. Because of the advantage offered by contrast variation and the Ångstrom resolution, neutron reflectivity is the ideal technique to study these systems.
DOI: 10.5286/isis.e.rb1510185
title: Hydrogen loading and unloading kinetics in thin Mg films

description: Hydrogen storage in metal hydrides has recently been studied as a possible way to store energy. One of the possible options is magnesium, which is abundant and cheap and it has a  high hydrogen storage capacity. However, its ability to release the hydrogen fast is limited. To overcome this problem, alternative approaches have been developed including the use of nanostructures or thin film systems. Recently, the loading and unloading of Mg thin films have been studied with optical hydrogenography. Results were interpreted as a two-phase system (Mg / MgH2), where the kinetics are described by a  nucleation and growth process. Studies of hydrogen loading of nano-sized Mg particles suggest more complicated kinetics. We propose to study this process in more detail by means of specular and off-specular neutron reflectometry.
DOI: 10.5286/isis.e.rb1510201
title: Proving the successful manufacturing of chemically-ordered L10 FeNi

description: The tetragonal chemically-ordered L10 FeNi phase has recently attracted significant attention for advanced permanent magnet applications due to its compelling magnetic properties, low cost and good availability of its constituent elements. While L10 FeNi has been found in meteorites, bulk synthesis has not yet been achieved due to its low order-disorder temperature of 320°C, below which phase formation is kinetically limited. The key objective of this proposed research is to explore pathways to synthesize L10 FeNi in earthly timeframes. Preliminary synchrotron XRD testing of our samples has provided initial evidence of successful formation of L10 FeNi. The higher resolution and flux available at HRPD provide a unique opportunity for L10-FeNi phase identification and characterization, to unambiguously prove the achievement of this phase in a laboratory setting.
DOI: 10.5286/isis.e.rb1510447
title: Rare Earth Pyrochlore Osmates  A New Family of 5d Transition Metal Oxides

description: 5d transition metal oxides host complex states combining electronic correlations, crystal electric fields and spin-orbit coupling on a similar energy scale. This delicate balance has excited theoretical interest, leading to predictions of topologically non-trivial band structures in the bulk (Weyl semimetal), novel quasiparticles (Majorana fermions) and superconductivity. In 5d TMOs of the pyrochlore structure, magnetic frustration adds to the complexity of the electronic ground state. We here propose the first in-depth study of rare earth pyrochlore osmates. We will determine the ordering of the osmium magnetic moments in Y2Os2O7 below 50 K. This will form an invaluable reference for a number of future projects, including first principles calculations, inelastic studies and characterisation of other pyrochlore rare earth osmates.
DOI: 10.5286/isis.e.rb1510466
title: Surface charge induced layering of ionic liquids on mica

description: The structure of ionic liquids at charged interfaces is an exciting and vibrant area of current research. Previous surface force apparatus experiments have shown layering up to 80 Å on mica in confined environments. Here we aim to study the ordered structure in a non-destructive and non-invasive way using neutron reflection to probe the mica surface without confinement.
DOI: 10.5286/isis.e.rb1510467
title: Internal phase strain evolution during high temperature deformation of model alpha-beta alloys

description: Alpha-beta Ti and Zr alloys are an important class of high strength alloys used in aerospace and nuclear power generation. They are unique in that their mechanical properties can be tailored by thermomechanical processing which consists of hot deformation and annealing. Although the basic physical processes occurring during this process are known, it is still not possible to computationally model the thermomechanical process and its effects on the property. This is because, during the process, several different physical processes are active which interact with each other in a complex way. Neutron diffraction makes it possible to study these processes in-situ and obtain unique data that can be used to decouple these interaction and help develop computational models. These models can then be used to optimise the process and help develop new alloys.
DOI: 10.5286/isis.e.rb1510586
title: Dynamics of polyaniline film growth, solvation and redox-evolution as a function of

description: We propose time-resolved specular neutron reflectivity (NR) measurements during electrodeposition of polyaniline (PAni) films via different electrochemical control functions: potentiostatic (PS), potentiodynamic (PD) and galvanostatic (GS). Motivation is provided by a huge literature on this process and material that reports widely divergent properties and performance - without underlying structural or compositional rationale - which inhibits optimization for device fabrication. We explore the concept that different electrochemical control functions generate films of different solvent content that, through viscosity effects, lead to variations in ion (¿dopant¿) transport rate and polymer chain dynamics. These in turn control device switching rate, mechanical stability and longevity.
DOI: 10.5286/isis.e.rb1561020
title: Characterization of neutron scattering and absorption properties of new types of concrete slabs
DOI: 10.5286/isis.e.rb1561021
title: Comparison between solid state and scintillation detectors as He-free thermal neutron detection devices for pulsed neutron sources
DOI: 10.5286/isis.e.rb1620034
title: Contrast variation using organogels with halophenols

description: Contrast variation Small-angle neutron scattering (CV-SANS) will be used to probe structure of novel organogels made from surfactants and p-halophenols as low molecular weight organogelators (LMOGs, Figure 2). Both the LMOG and the surfactant are commercially available. There is no literature on CV-SANS on these systems. Alongside this, the use of halophenols brings phase transition temperature of the gels to an appropriate temperature region (Figure 3), and forms stronger gels than the hydrocarbon phenols previously documented 1-2, increasing their potential for use with CO2-philic surfactants.
DOI: 10.5286/isis.e.rb1620062
title: Water diffusion mechanism in hydrated amorphous calcium carbonate

description: Calcium carbonates are highly important in geochemistry and especially in biomineralization. In nature, organisms can form each of the anhydrous polymorphs selectively for various purposes from precursor amorphous calcium carbonate (ACC). the stability of ACC can be controlled by incorporating various ions such as Mg and Phosphate. The stabilising effect of these ions is generally attributed to their strong interaction with water. By binding water more strongly they should create bottle necks for water diffusion and thereby lower the overall diffusion. This we plan to study using QENS on ACC and it's Mg and Phosphate equivalents as well mixtures of the these three compounds.
DOI: 10.5286/isis.e.rb1620084
title: Investigating the effect of magnetic impurities on ALC resonances

description: This proposal aims to investigate the effect of magnetic impurities on the ALC resonance amplitude of an organic semiconductor (RRa-P3HT), to determine whether the effect can be quantified. Previous measurements have found that for a small concentration of magnetic impurities (0.004%), a 10% increase in the ALC amplitude occurs at 300K. In this experiment, we propose to systematically change the magnetic impurity concentration in the RRa-P3HT, from 0.001% to 0.02% to determine how the ALC amplitude changes. The ALC resonances will also be model to allow for further understanding and quantification of the different processes contributing to the overall magnitude.
DOI: 10.5286/isis.e.rb1620158
title: Structure property relationships in new lead-free ceramics for energy storage

description: There has been much recent research on the development of lead-free ceramics to replace lead zirconium titanate, which is widely used in a variety of electronic devices including actuators, sensors, transducers and capacitors. In the present proposal we investigate bismuth niobium titanate-barium strontium titanate based materials, which are of particular interest as their high dielectric constant and low dielectric loss can be utilized for energy storage in capacitors (which have higher power density compared to batteries). Their energy density is significantly better than many ferroelectric ceramics currently used for energy storage. The aim of the present work is to establish the structure property relationships in this system and confirm the structural details of the critical phase transitions in this system.
DOI: 10.5286/isis.e.rb1620180
title: Suppression of thermal conductivity in nanostructured ZnO at elevated temperatures

description: Thermoelectricity offers solutions for the low-carbon economy through the development of energy efficient technology. Modest improvement in thermoelectric performance would allow, for example, waste heat in car exhausts to be converted into useful power, and hot spots on computer chips to be cooled using solid state refrigerators. However, most thermoelectric materials have complicated structures with scarce or harmful elements. Zinc oxide and its alloys are attractive candidates because of their simplicity, high thermal stability, corrosion resistance, non-toxicity and low cost. The electronic transport of zinc oxide is ideal for thermoelectric applications, but its thermal conductivity is too high. However, nanostructuring reduces the thermal conductivity by an order of magnitude. We aim to understand this phenomenon by measuring lattice vibrations using inelastic neutron scattering.
DOI: 10.5286/isis.e.rb1620335
title: SANS study of the effect of thermal annealing on the morphology of bulk heterojunction PffBT4T-2OD:fullerene thin films

description: This projects aims to contribute to a better understanding of the relationship between processing conditions, active layer morphology and device performance in polymer solar cells (PSCs). To this end a series of SANS experiments are envisaged, to provide the most detailed understanding possible of the processing-morphology-performance relationships in polymer:fullerene solar cells based on a polymer with the best power conversion efficiencies (PCEs), namely PffBT4T-2OD (also known as PCE11). Optimized organic photovoltaic (OPV) processing, with its associated low production costs, would radically change the renewable energy paradigm that is key for opening solar energy to new markets such as those in developing countries where people would notnormally think about investing in and generating their own electricity.
DOI: 10.5286/isis.e.rb1700006
title: Structure of hyaluronic acid solutions in aqueous and salt environment
DOI: 10.5286/isis.e.rb1700052
title: Measurements of single-event burn-out of HV power devices for different technology nodes

description: High-voltage power semiconductor devices, such as IGBTs, diodes and MOSFETs are susceptible to destructive failure due to terrestrial cosmic radiation (CR). As a consequence, device development has to ensure adequate radiation hardness for every device technology. This aim can only partly be met by device and technology simulations and, therefore, also calls for extensive device tests. In order to reduce testing times accelerated irradiation tests at facilities with a nucleon energy spectrum close to the natural terrestrial CR are essential. The thus obtained failures rates will be compared to simulation predictions and storage tests. A further aim is the close comparison of results obtained at different accelerator facilities to ensure the relevance and quality of the device tests. This latter goal is important as no single radiation facility is able to perfectly match the natural CR.
DOI: 10.5286/isis.e.rb1710079
title: Looking at the motion associated with the cation and their freezing in TEA(TCNQ)2 using QENS

description: The study of organic based materials is a popular topic and spans both chemistry and physics and presents some significant advantages. Of interest within this proposal is the compound tetraethylammonium bis-7,7,8,8-tetracyanoquinodimethane (TEA(TCNQ)2)) where the sample has recently been shown to have anomolies within the dielectric data at both the structural and magentic transitions, illustrating it's potential as a dielectric material. However, little is known about the structural aspects of the high temeprature transition where the TEA cations freeze into, what is believed to be a disordered structure. The protons are key as these flucutate around the nitrogen and up till now, no neutron study has been performed at these high temepratures. This study will allow us to look at how these TEA cations ion flucutatue by probing length and time scales of these motions.
DOI: 10.5286/isis.e.rb1710148
title: QENS studies of conductivity/hydride diffusion in barium hydride

description: BaH2 has application in hydrogen storage technologies. We propose to study BaH2 by Quasi-elastic neutron scattering. We will perform scans at different temperatures for up twelve hours. The peak broadening will then be associated with local ion movements allowing us to extract diffusion coefficients and theoretical conductivity values. We plan to use an in-situ cell to measure conductivity. We can compare the two conductivity values and investigate any discrepancies.  In our experiment, the change in neutron energies after diffraction will allow us to determine how hydride (H-) ions move inside the BaH2 solid. Understanding the movement of ions in solid materials is very important in the development of new technologies allowing for the storage and use of hydrogen as an energy source.