cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1920152-1
title: Crystal Electric Field (CEF) Effect in CeIr3Ge7 and YbIr3Ge7

description: We recently discovered new members of the stoichiometric 1-3-7 family of crystals including YbRh3Si7, YbIr3Ge7, CeIr3Ge7, and YbIr3Si7, whose magnetic and transport properties reflect large crystal electric field(CEF) anisotropy. Inelastic neutron scattering measurements on CeIr3Ge7 and YbIr3Ge7 will allow us to directly measure their CEF transitions from which we can then parameterize their single ion Hamiltonians. This analysis will definitively establish the nature of their spin anisotropies and the g-tensor of their ground state doublet, from which we can determine the size of the magnetic moment reduced by crystal field effects. Our studies thus far have revealed the importance of single ion properties in these two materials and it is thus crucial that we directly measure their CEF schemes to understand the origins of these effects.
DOI: 10.5286/isis.e.rb1920258
title: Combining Molecular Dynamics Simulations with QENS to improve the current water models for understand the dynamics of water molecules in NaX

description: The structure and dynamics of water molecules in the presence of non-trivial confinement in porous systems has always created a lot of interest, both from an experimental and theoretical point of view. Specifically, inorganic materials used as hosts of small guest molecules are important for industrial and environmental applications. In the case of NaX, which have industrial application, several studies have been carried out with the objective of obtaining more clues about how the behaviour of the confined water is. We propose to employ QENS to measure the diffusivity of H2O within the faujasite NaX holes as a function of water content at three different temperatures and compare and test the accuracy of current water models.
DOI: 10.5286/isis.e.rb1920258-1
title: Combining Molecular Dynamics Simulations with QENS to improve the current water models for understand the dynamics of water molecules in NaX

description: The structure and dynamics of water molecules in the presence of non-trivial confinement in porous systems has always created a lot of interest, both from an experimental and theoretical point of view. Specifically, inorganic materials used as hosts of small guest molecules are important for industrial and environmental applications. In the case of NaX, which have industrial application, several studies have been carried out with the objective of obtaining more clues about how the behaviour of the confined water is. We propose to employ QENS to measure the diffusivity of H2O within the faujasite NaX holes as a function of water content at three different temperatures and compare and test the accuracy of current water models.
DOI: 10.5286/isis.e.rb1920304
title: Substrate-dependent structure of grafted polymer films

description: Hydrogels are water-rich polymer networks made from natural or synthetic polymers, which are widely used in biomaterials, medicine and antifouling. We explore PEG-based hydrogels grafted through a UV-initiated free-radical polymerization, primarily for antifouling applications. Their preparation can be tuned to produce a given polymer mass per surface area, but growth rates vary between substrate types, and is 2-4 times faster on gold than on silicon; two substrate types which are important for biosensors. Previous data point at variations in grafting densities as a reason for this, and to further investigate this, we compare the structures of polymers grafted from surfaces with controlled surface densities of initiators, using dilution of initiators in mixed monolayers of alkylthiols on gold, and organosilanes on silicon.
DOI: 10.5286/isis.e.rb1920304-1
title: Substrate-dependent structure of grafted polymer films

description: Hydrogels are water-rich polymer networks made from natural or synthetic polymers, which are widely used in biomaterials, medicine and antifouling. We explore PEG-based hydrogels grafted through a UV-initiated free-radical polymerization, primarily for antifouling applications. Their preparation can be tuned to produce a given polymer mass per surface area, but growth rates vary between substrate types, and is 2-4 times faster on gold than on silicon; two substrate types which are important for biosensors. Previous data point at variations in grafting densities as a reason for this, and to further investigate this, we compare the structures of polymers grafted from surfaces with controlled surface densities of initiators, using dilution of initiators in mixed monolayers of alkylthiols on gold, and organosilanes on silicon.
DOI: 10.5286/isis.e.rb1920540
title: Phase transitions in Sr-doped multiferroic bismuth ferrite

description: Bismuth ferrite, BiFeO3, is a much-studied ceramic showing both dielectric and magnetic ordering at relatively high temperatures. In order to improve its properties there has been much interest in doping BiFeO3, but rarely has there been structural characterisation of these materials. We have shown that it is possible to replace bismuth ions by strontium together with oxygen vacancies. Increasing composition of strontium lowers the transition temperatures so that the high-symmetry cubic phase becomes stable at room temperature, but with remaining antiferromagnet and ferromagnetic order. We will use high-resolution powder diffraction to study the ferroelectric phase transitions as a function of temperature in samples of different Sr-content.
DOI: 10.5286/isis.e.rb1920540-1
title: Phase transitions in Sr-doped multiferroic bismuth ferrite

description: Bismuth ferrite, BiFeO3, is a much-studied ceramic showing both dielectric and magnetic ordering at relatively high temperatures. In order to improve its properties there has been much interest in doping BiFeO3, but rarely has there been structural characterisation of these materials. We have shown that it is possible to replace bismuth ions by strontium together with oxygen vacancies. Increasing composition of strontium lowers the transition temperatures so that the high-symmetry cubic phase becomes stable at room temperature, but with remaining antiferromagnet and ferromagnetic order. We will use high-resolution powder diffraction to study the ferroelectric phase transitions as a function of temperature in samples of different Sr-content.
DOI: 10.5286/isis.e.rb1920662
title: Understanding the interactions between organic template and metal cations to assemble zeolite frameworks

description: Zeolites are highly crystalline aluminosilicate materials which are characterised by their microporosity and open framework structures. Due to their porosity, zeolites have a variety of applications including catalysis, hydrocracking, ion-exchange and as drug release materials. Many zeolites are made using organic structure directing agents (OSDA). We intend to use inelastic neutron scattering (INS) spectroscopy on the TOSCA instrument to probe the OSDA - tetramethylammonium molecule in three zeolite structures. This will give an indication as to how tetramethylammonium molecule is occupying the zeolite cavity, allowing us also to identify its possible shape and interaction with the zeolite framework. This will lead to better understanding as to what role tetramethylammonium plays in synthesis of those zeolites, and to the general understanding of OSDA role in zeolite synthesis.
DOI: 10.5286/isis.e.rb1920662-1
title: Understanding the interactions between organic template and metal cations to assemble zeolite frameworks

description: Zeolites are highly crystalline aluminosilicate materials which are characterised by their microporosity and open framework structures. Due to their porosity, zeolites have a variety of applications including catalysis, hydrocracking, ion-exchange and as drug release materials. Many zeolites are made using organic structure directing agents (OSDA). We intend to use inelastic neutron scattering (INS) spectroscopy on the TOSCA instrument to probe the OSDA - tetramethylammonium molecule in three zeolite structures. This will give an indication as to how tetramethylammonium molecule is occupying the zeolite cavity, allowing us also to identify its possible shape and interaction with the zeolite framework. This will lead to better understanding as to what role tetramethylammonium plays in synthesis of those zeolites, and to the general understanding of OSDA role in zeolite synthesis.
DOI: 10.5286/isis.e.rb1920180
title: Magnetic configuration of an epitaxial thin film of U2N3

description: UN is a prominent advanced nuclear fuel, due to its high uranium density and good thermal conductivity. However, its dissolution in water is worse than that of UO2 and is poorly understood. A strong possibility is that there are U6+ ions present, as these are known to be highly soluble, as opposed to the normal U4+ ions that dominate UO2 and are insoluble in water. These U6+ ions could come from U2N3, which is formed at the UN interface on oxidation and contains two U sites. U2N3 orders antiferromagnetically, and experiments on a thin epitaxial film at Diamond in Jan 2019 showed AF order at ~ 73 K with q = 1. No bulk single crystals exist and the phase is hard to stabilize. Since U6+ has no 5f electrons it cannot support magnetic order. We wish to measure the intensities of the first 6 AF reflections to determine the individual moments, and hence whether such a U6+ site exists.
DOI: 10.5286/isis.e.rb1920180-1
title: Magnetic configuration of an epitaxial thin film of U2N3

description: UN is a prominent advanced nuclear fuel, due to its high uranium density and good thermal conductivity. However, its dissolution in water is worse than that of UO2 and is poorly understood. A strong possibility is that there are U6+ ions present, as these are known to be highly soluble, as opposed to the normal U4+ ions that dominate UO2 and are insoluble in water. These U6+ ions could come from U2N3, which is formed at the UN interface on oxidation and contains two U sites. U2N3 orders antiferromagnetically, and experiments on a thin epitaxial film at Diamond in Jan 2019 showed AF order at ~ 73 K with q = 1. No bulk single crystals exist and the phase is hard to stabilize. Since U6+ has no 5f electrons it cannot support magnetic order. We wish to measure the intensities of the first 6 AF reflections to determine the individual moments, and hence whether such a U6+ site exists.
DOI: 10.5286/isis.e.rb1920288
title: Hydrogen groups associated with no graphitic carbon domains in biowaste derived carbons for energy applications

description: Carbonized biowaste presents a promising route to producing energy materials in a low carbon or even carbon negative way, given that the precursor material (i.e. plant material) relies on the conversion of atmospheric CO2 to sugar molecules. By treating cellulose, starch or other sugar molecules at high temperature (230 oC) and pressure in aqueous solution, an amorphous high carbon material is formed. This hydrothermal carbon (HTC) can be further modified to produce parts for battery anodes, water purification filters, supercapacitors, fuel cells and catalyst supports. Here we propose to examine the hydrogen group of the HTC carbon material before and after heat treatment at relatively low temperatures to better understand the nature of the disordered carbon material.
DOI: 10.5286/isis.e.rb1920288-1
title: Hydrogen groups associated with no graphitic carbon domains in biowaste derived carbons for energy applications

description: Carbonized biowaste presents a promising route to producing energy materials in a low carbon or even carbon negative way, given that the precursor material (i.e. plant material) relies on the conversion of atmospheric CO2 to sugar molecules. By treating cellulose, starch or other sugar molecules at high temperature (230 oC) and pressure in aqueous solution, an amorphous high carbon material is formed. This hydrothermal carbon (HTC) can be further modified to produce parts for battery anodes, water purification filters, supercapacitors, fuel cells and catalyst supports. Here we propose to examine the hydrogen group of the HTC carbon material before and after heat treatment at relatively low temperatures to better understand the nature of the disordered carbon material.
DOI: 10.5286/isis.e.rb1920336
title: Residual stress characterisation of machining on a wire arc additively manufactured component

description: Wire Arc Additive Manufacturing (WAAM) is a rapid and cost effective approach that is suited to the production of large components. Machining of these parts is difficult due to variations in surface roughness and part distortions and therefore specialised techniques have recently been developed. In order to use these methods reliably, an enhanced understanding of the residual stress generated (& relieved) by these approaches is required. In this study time of flight neutron diffraction will be performed to map lattice strain variation in 3D within a Ti-6Al-4V WAAM part before and after machining. These results will be used to optimise existing models of production and will be used to tailor machining parameters. Such insights are critically required in order to validate these new processing routines and facilitate reliable industrial use of this highly promising production methodology.
DOI: 10.5286/isis.e.rb2000052
title: Elucidation of dynamic structural characteristics of γ-Na3PS4 plastic crystal through neutron-PDF

description: We aim to further clarify the atomic scale structure of a novel phase of the Na3PS4 solid ion conductor. This phase appears to possess ideal properties to be used as a solid electrolyte for applications such as next-generation batteries. These properties include superionic, liquid-like mobility of Na+ ions with extremely low resistance while maintaining a solid nature that can lead to solid-state batteries with increased safety and performance. Understanding the intricacies of this material can lead to fundamental advances in materials science as well as practical breakthroughs in battery technology.
DOI: 10.5286/isis.e.rb2000102
title: ChipIR Commercial Access Infineon OX12 - week51/2019

description: High-voltage power semiconductor devices, such as IGBTs, diodes and MOSFETs are susceptible to destructive failure due to terrestrial cosmic radiation (CR), notably the nucleon part. 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.
DOI: 10.5286/isis.e.rb2000102-1
title: ChipIR Commercial Access Infineon OX12 - week51/2019

description: High-voltage power semiconductor devices, such as IGBTs, diodes and MOSFETs are susceptible to destructive failure due to terrestrial cosmic radiation (CR), notably the nucleon part. 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.
DOI: 10.25810/fx6e-r462.7
title: European Newspaper Coverage of Climate Change or Global Warming, 2004-2019 - October 2019

description: The Media and Climate Change Observatory Data monitors 74 sources (across newspapers, radio and TV) in 38 countries in seven different regions around the world. Data is assembled by accessing archives through the Lexis Nexis, Proquest and Factiva databases via the University of Colorado libraries. More information may be found at: http://sciencepolicy.colorado.edu/icecaps/research/media_coverage/index.html. These data include Excel (.xlsx), CSV (.csv), and plain-text README files (.txt).
DOI: 10.5286/isis.e.rb1910262
title: Variable temperature structural study of disordered La0.5Ba0.5CoO3-d; and layered LnBaCo2O6-d; (Ln = La, Y) perovskites

description: The aim of the proposal is to investigate changes in the crystal structure of A-site disordered La0.5Ba0.5CoO3-d; and layered LnBaCo2O6-d; (Ln = La, Y) perovskites at high-temperatures under a nitrogen atmosphere. These materials show reversible loss and gain of oxygen under temperature cycling and are of interest for a wide range of applications including as cathodes in solid oxide fuel cells. We are interested in chemical looping, where the oxidation/reduction of the metal oxide is used to drive chemical reactions. This experiment will enable us to determine which oxygen sites are preferably emptied and re-populated. Variable temperature neutron powder diffraction studies on the analogous Pr and Nd materials have been reported but there is no detailed neutron study of the La and Y materials yet, perhaps due the greater difficulty in synthesising phase pure materials.
DOI: 10.5286/isis.e.rb1910262-1
title: Variable temperature structural study of disordered La0.5Ba0.5CoO3-d; and layered LnBaCo2O6-d; (Ln = La, Y) perovskites

description: The aim of the proposal is to investigate changes in the crystal structure of A-site disordered La0.5Ba0.5CoO3-d; and layered LnBaCo2O6-d; (Ln = La, Y) perovskites at high-temperatures under a nitrogen atmosphere. These materials show reversible loss and gain of oxygen under temperature cycling and are of interest for a wide range of applications including as cathodes in solid oxide fuel cells. We are interested in chemical looping, where the oxidation/reduction of the metal oxide is used to drive chemical reactions. This experiment will enable us to determine which oxygen sites are preferably emptied and re-populated. Variable temperature neutron powder diffraction studies on the analogous Pr and Nd materials have been reported but there is no detailed neutron study of the La and Y materials yet, perhaps due the greater difficulty in synthesising phase pure materials.
DOI: 10.5286/isis.e.rb1920228
title: Hydrophobically modified nanocelluloses/starch hydrogels: Enhancing hydrophobic interactions and inclusion complex formation

description: This proposal aims to investigate the interaction of hydrophobically modified oxidised cellulose nanofibrils (HM-OCNF) with surfactants or soluble starch, in order to find new more environmentally friendly rheology modifiers for possible applications in personal care or agrochemicals. Hydrophobic modification via attachment of C8 or C12 hydrocarbon chains to the cellulose particle surface has been shown to result in greatly enhanced interactions with soluble starch, dramatically increasing the viscosity of these suspensions. Here we wish to determine whether the hydrophobic chains are forming inclusion complexes with the amylose-rich soluble starch, or with micelles to better understand the mechanism of interaction between these species. We will take advantage of selective deuteration of the Cn chain and the solvent to provide scattering contrast in these systems.
DOI: 10.5286/isis.e.rb1920228-1
title: Hydrophobically modified nanocelluloses/starch hydrogels: Enhancing hydrophobic interactions and inclusion complex formation

description: This proposal aims to investigate the interaction of hydrophobically modified oxidised cellulose nanofibrils (HM-OCNF) with surfactants or soluble starch, in order to find new more environmentally friendly rheology modifiers for possible applications in personal care or agrochemicals. Hydrophobic modification via attachment of C8 or C12 hydrocarbon chains to the cellulose particle surface has been shown to result in greatly enhanced interactions with soluble starch, dramatically increasing the viscosity of these suspensions. Here we wish to determine whether the hydrophobic chains are forming inclusion complexes with the amylose-rich soluble starch, or with micelles to better understand the mechanism of interaction between these species. We will take advantage of selective deuteration of the Cn chain and the solvent to provide scattering contrast in these systems.
DOI: 10.5286/isis.e.rb1920332
title: Magnetism in a spin 1/2 honeycomb coordination polymer antiferromagnet

description: The possibility of stabilizing quantum disordered spin liquid states on a honeycomb lattice has led to much research into magnetic systems that adopt this structure, but which also allow the flexibility to make subtle structural changes to tune the interactions. In this proposal we aim to elucidate the low-temperature magnetic properties of a new coordination-polymer-based S = 1/2 honeycomb lattice antiferromagnet, Cu(pym)1.5(H2O)(BF4)2, which could provide the flexible framework needed to tune the magnetic interactions within the honeycomb lattice paradigm. The low temperature magnetic behaviour of this material is currently mysterious, but it is likely that implanted muons can determine its low energy ground state and elucidate its excitations.
DOI: 10.5286/isis.e.rb1920332-1
title: Magnetism in a spin 1/2 honeycomb coordination polymer antiferromagnet

description: The possibility of stabilizing quantum disordered spin liquid states on a honeycomb lattice has led to much research into magnetic systems that adopt this structure, but which also allow the flexibility to make subtle structural changes to tune the interactions. In this proposal we aim to elucidate the low-temperature magnetic properties of a new coordination-polymer-based S = 1/2 honeycomb lattice antiferromagnet, Cu(pym)1.5(H2O)(BF4)2, which could provide the flexible framework needed to tune the magnetic interactions within the honeycomb lattice paradigm. The low temperature magnetic behaviour of this material is currently mysterious, but it is likely that implanted muons can determine its low energy ground state and elucidate its excitations.
DOI: 10.5286/isis.e.rb1920336-1
title: Residual stress characterisation of machining on a wire arc additively manufactured component

description: Wire Arc Additive Manufacturing (WAAM) is a rapid and cost effective approach that is suited to the production of large components. Machining of these parts is difficult due to variations in surface roughness and part distortions and therefore specialised techniques have recently been developed. In order to use these methods reliably, an enhanced understanding of the residual stress generated (& relieved) by these approaches is required. In this study time of flight neutron diffraction will be performed to map lattice strain variation in 3D within a Ti-6Al-4V WAAM part before and after machining. These results will be used to optimise existing models of production and will be used to tailor machining parameters. Such insights are critically required in order to validate these new processing routines and facilitate reliable industrial use of this highly promising production methodology.
DOI: 10.5286/isis.e.rb1920434
title: Quantum dots with deuterated oleic acid shells and their functionalisation with singlet fission ligands

description: Our research aims to develop plastic films that change the colour of the light that passes through them, not by absorbing certain wavelengths of light, as a simple colour filter would, but by converting light of one wavelength to another without losing any energy. Such a film, applied to a silicon solar cell, could make it up to 30% more efficient. To do this we need to make semiconductor nanocrystals, coat them with a very thin layer of an organic semiconductor so the two materials are in molecular contact. Then we have to disperse these tiny composite nanoparticles in a clear plastic film, as evenly as possible and without clumping. Small angle neutron scattering allows to pick out the shapes of the composite nanoparticles and their component parts, and the way they interact each other, helping us to design routes to make these "photon multiplier" films.