cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb2010469-1
title: In situ INS Studies of Decorated Zeolites for Alkyne/Alkene Separations

description: Efficient removal of alkyne impurities for the production of polymer-grade lower olefins remains an important and challenging target for many industries. We seek to develop highly selecitve zeolites as efficient alkyne/alkene separation materials and request 3 days on TOSCA to study the binding sites of adsorbed hydrocarbon molecules (C2H2/C2H4/C3H4/C3H6) within a top-performing zeolite, Ni@FAU. Under ambient conditions, Ni@FAU shows exceptional adsorption of alkynes and efficient separations of acetylene/ethylene and propyne/propylene mixtures with unprecedented separation selectivities of 100 and 92, respectively. This proposal will investigate the host-guest binding dynamics and define the mechanism of active Ni sites. The proposed study aims to reveal the nature of this interaction through vibrational insights.
DOI: 10.5286/isis.e.rb2000172
title: Variable temperature characterisation of a new family of Li ion conductors

description: We aim to perform variable temperature neutron diffraction to characterise a new family of lithium ion conductors: the hexagonal argyrodites. The activation barriers associated with ion transport in bulk crystalline structures are determined by the local coordination environments of the mobile ion, Li in this case. Accurate structural characterisation of the crystal structures of new Li ion conductors is necessary to understand mechanisms for ion transport. Neutron diffraction makes this possible, overcoming the difficulties encountered with weak X-ray scattering of Li. The new material exhibits a phase transition to a disordered structure establishing a relationship between well-known argyrodite and anti-perovskite ion conductors. The sample is ready to be measured and has been characterised using synchrotron X-ray diffraction (I11), measurement ionic conductivity and thermal behaviour.
DOI: 10.5286/isis.e.rb2000172-1
title: Variable temperature characterisation of a new family of Li ion conductors

description: We aim to perform variable temperature neutron diffraction to characterise a new family of lithium ion conductors: the hexagonal argyrodites. The activation barriers associated with ion transport in bulk crystalline structures are determined by the local coordination environments of the mobile ion, Li in this case. Accurate structural characterisation of the crystal structures of new Li ion conductors is necessary to understand mechanisms for ion transport. Neutron diffraction makes this possible, overcoming the difficulties encountered with weak X-ray scattering of Li. The new material exhibits a phase transition to a disordered structure establishing a relationship between well-known argyrodite and anti-perovskite ion conductors. The sample is ready to be measured and has been characterised using synchrotron X-ray diffraction (I11), measurement ionic conductivity and thermal behaviour.
DOI: 10.5286/isis.e.rb2010259
title: Phonons under pressure in a barocaloric framework material

description: Conventional vapour-compression refrigeration relies on refrigerants that contribute both to global warming and ozone depletion. Barocaloric materials, in which a large isothermal entropy change is associated with a pressure-induced phase transition, offer an eco-friendly alternative. The framework material TPrAMn(dca)3 has recently been shown to have a giant barocaloric effect, due to an order-disorder phase transition involving both the dca and TPrA ions. Understanding the dynamics of this material under pressure is vital to explaining and optimising this material’s functional behaviour. In this proposal, we aim to do this by measuring the phonon dispersion on MERLIN. Together with our scheduled study of this material’s crystallographic structure on GEM, this will provide a complete picture of this material’s remarkable properties.
DOI: 10.5286/isis.e.rb2010259-1
title: Phonons under pressure in a barocaloric framework material

description: Conventional vapour-compression refrigeration relies on refrigerants that contribute both to global warming and ozone depletion. Barocaloric materials, in which a large isothermal entropy change is associated with a pressure-induced phase transition, offer an eco-friendly alternative. The framework material TPrAMn(dca)3 has recently been shown to have a giant barocaloric effect, due to an order-disorder phase transition involving both the dca and TPrA ions. Understanding the dynamics of this material under pressure is vital to explaining and optimising this material’s functional behaviour. In this proposal, we aim to do this by measuring the phonon dispersion on MERLIN. Together with our scheduled study of this material’s crystallographic structure on GEM, this will provide a complete picture of this material’s remarkable properties.
DOI: 10.5286/isis.e.rb2010626
title: Coupling between perpendicular and in-plane magnetic anisotropy layers in amorphous heterostructures.

description: In magnetic recording media the superparamagnetic effect refers to the spontaneous change in magnetization due to thermal instability,caused by size limitation of the magnetically decoupled grains of the recording material. To combat this effect it has been proposed to use tilted magnetic recording materials, where the top magnetic layer is tilted from the film normal. We propose to use amorphous heterostructures composed of exchange coupled layers with in-plane and perpendicular magnetic anisotropy to achieve tilted magnetic anisotropy. There is great potential for engineering amorphous heterostructures so that they display a specific complex magnetic response. We propose to use polarized neutron reflectivity to determine the magnetic profile of such structures. This will allow the design of heterostructures with predefined magnetization and switching characteristics.
DOI: 10.5286/isis.e.rb2010626-1
title: Coupling between perpendicular and in-plane magnetic anisotropy layers in amorphous heterostructures.

description: In magnetic recording media the superparamagnetic effect refers to the spontaneous change in magnetization due to thermal instability,caused by size limitation of the magnetically decoupled grains of the recording material. To combat this effect it has been proposed to use tilted magnetic recording materials, where the top magnetic layer is tilted from the film normal. We propose to use amorphous heterostructures composed of exchange coupled layers with in-plane and perpendicular magnetic anisotropy to achieve tilted magnetic anisotropy. There is great potential for engineering amorphous heterostructures so that they display a specific complex magnetic response. We propose to use polarized neutron reflectivity to determine the magnetic profile of such structures. This will allow the design of heterostructures with predefined magnetization and switching characteristics.
DOI: 10.5286/isis.e.rb2010226
title: INS STUDY OF BIOCHAR AS SOLID ACID CATALYSTS

description: Pyrolysis is considered as a sustainable way to generate energy from bio-oil, however, biochar – a solid residue by-product– is inevitably produced in the production line. We have previously attempted to modify biochar as a solid acid catalyst with magnetic functionality. The material showed promising catalytic activity for the esterification of oleic acid and methanol to give a 64% yield of FAME (biodiesel). In order to optimise their catalytic performance, a deeper understanding of the surface properties of biochar is essential. INS is ideally suited for the investigation of carbon-rich amorphous materials. We would like to understand the surface chemistry and details of the interaction between the catalyst and the oleic acid adsorbate. The use of biochar as a low cost and renewable carbon based solid acid catalyst will open new applications in industrial catalysis.
DOI: 10.5286/isis.e.rb2010226-1
title: INS STUDY OF BIOCHAR AS SOLID ACID CATALYSTS

description: Pyrolysis is considered as a sustainable way to generate energy from bio-oil, however, biochar – a solid residue by-product– is inevitably produced in the production line. We have previously attempted to modify biochar as a solid acid catalyst with magnetic functionality. The material showed promising catalytic activity for the esterification of oleic acid and methanol to give a 64% yield of FAME (biodiesel). In order to optimise their catalytic performance, a deeper understanding of the surface properties of biochar is essential. INS is ideally suited for the investigation of carbon-rich amorphous materials. We would like to understand the surface chemistry and details of the interaction between the catalyst and the oleic acid adsorbate. The use of biochar as a low cost and renewable carbon based solid acid catalyst will open new applications in industrial catalysis.
DOI: 10.5286/isis.e.rb2010193
title: Comparison of the structural behaviour of two flavins at the electrode/electrolyte interface under applied potential.

description: This proposal concerns the structural behaviour of two flavins that act as mediators between electroactive biofilms and electrodes by transferring electrons from the bacterial cell membrane to the electrode surface. This is currently the rate-limiting step in bioelectrochemical devices that use these light-harvesting biofilms to generate electricity and the nature of the biofilm/electrode interaction remains poorly understood. Specifically, it has been proposed from previous electrochemical measurements that the two flavins (that differ only by one phosphate group) may form very different structures at the electrode surface and may behave differently when a potential is applied. However, structural analysis of these systems is lacking and so neutron reflectometry offers the perfect technique to verify or reassess these predictions in situ using a custom-made electrochemical cell.
DOI: 10.5286/isis.e.rb2010193-1
title: Comparison of the structural behaviour of two flavins at the electrode/electrolyte interface under applied potential.

description: This proposal concerns the structural behaviour of two flavins that act as mediators between electroactive biofilms and electrodes by transferring electrons from the bacterial cell membrane to the electrode surface. This is currently the rate-limiting step in bioelectrochemical devices that use these light-harvesting biofilms to generate electricity and the nature of the biofilm/electrode interaction remains poorly understood. Specifically, it has been proposed from previous electrochemical measurements that the two flavins (that differ only by one phosphate group) may form very different structures at the electrode surface and may behave differently when a potential is applied. However, structural analysis of these systems is lacking and so neutron reflectometry offers the perfect technique to verify or reassess these predictions in situ using a custom-made electrochemical cell.
DOI: 10.5286/isis.e.rb2010189
title: Magnetic excitations in a tuneable S = 1/2 spin ladder system near quantum criticality

description: Spin ladders are excellent model systems for studying quantum phase transitions, as they exhibit a quantum critical point between non-magnetic spin singlet dimers to Néel magnetic order as inter-ladder exchange is increased. Ba2CuTeO6 is a Cu2+ S = 1/2 two-leg spin ladder system, that is close to the quantum critical point on the Néel ordered side. By replacing Te with W in a Ba2CuTe1-xWxO6 solid solution, we have managed to suppress the magnetic order as indicated by muon spin rotation measurements. We will use inelastic neutron scattering to study magnetic excitations in these doped samples. This will allow us to establish whether we have succeeded in stabilizing a spin singlet ground state and to study quantum criticality near the QCP.
DOI: 10.5286/isis.e.rb2010189-1
title: Magnetic excitations in a tuneable S = 1/2 spin ladder system near quantum criticality

description: Spin ladders are excellent model systems for studying quantum phase transitions, as they exhibit a quantum critical point between non-magnetic spin singlet dimers to Néel magnetic order as inter-ladder exchange is increased. Ba2CuTeO6 is a Cu2+ S = 1/2 two-leg spin ladder system, that is close to the quantum critical point on the Néel ordered side. By replacing Te with W in a Ba2CuTe1-xWxO6 solid solution, we have managed to suppress the magnetic order as indicated by muon spin rotation measurements. We will use inelastic neutron scattering to study magnetic excitations in these doped samples. This will allow us to establish whether we have succeeded in stabilizing a spin singlet ground state and to study quantum criticality near the QCP.
DOI: 10.5286/isis.e.rb2010363
title: Lipid membrane interactions of virus-like mesoporous silica loaded with photocatalytic TiO2 nanoparticles

description: TiO2 nanoparticles (NPs) offer interesting possibilities in the context of antibiotic resistance and bacteria killing, as they are strongly antimicrobial by UV irradiation due to the generation of highly reactive oxygen species that attack the bacterial membrane. They can be loaded into mesoporous silica NPs, versatile carriers with mesopores that allow precise cargo loading and release. Here, we propose to study by neutron reflectometry the mutual structural and photooxidative effects of TiO2-loaded silica NPs, in the absence or presence of UV exposure, using anionic lipid bilayers as bacterial membrane models. We will also explore different morphologies by comparing smooth vs virus-like silica NPs, whose spikey nanotubes induce a direct mechanical action on membranes, providing novel insight into the interplay between NP topology and oxidative stress for membrane destabilization.
DOI: 10.5286/isis.e.rb2010363-1
title: Lipid membrane interactions of virus-like mesoporous silica loaded with photocatalytic TiO2 nanoparticles

description: TiO2 nanoparticles (NPs) offer interesting possibilities in the context of antibiotic resistance and bacteria killing, as they are strongly antimicrobial by UV irradiation due to the generation of highly reactive oxygen species that attack the bacterial membrane. They can be loaded into mesoporous silica NPs, versatile carriers with mesopores that allow precise cargo loading and release. Here, we propose to study by neutron reflectometry the mutual structural and photooxidative effects of TiO2-loaded silica NPs, in the absence or presence of UV exposure, using anionic lipid bilayers as bacterial membrane models. We will also explore different morphologies by comparing smooth vs virus-like silica NPs, whose spikey nanotubes induce a direct mechanical action on membranes, providing novel insight into the interplay between NP topology and oxidative stress for membrane destabilization.
DOI: 10.5286/isis.e.rb2010705
title: Neutron Diffraction Study of Perovskite Photocatalysts

description: Photocatalytic water splitting is of significant interest due to the potential utilization of renewable solar energy for production of clean and green H2 fuel. Among various metal oxide based photocatalysts, perovskite oxides are promising. In a ABO3 perovskite structure, changing stoichiometry or creating A or B site defects by incorporating cations with different valency and size facilitates interesting properties. Moreover, exsolution of light absorbing nanoparticles from the perovskite lattice can result in improved photocatalysts. The aim of this neutron diffraction study is to explore and improve understanding of the substitution and exsolution mechanism in the perovskite lattice and therefore its influence on photocatalysis can be correlated. Furthermore, this will enable us to optimize and develop a new class of photocatalyst materials with enhanced energy conversion efficiency.
DOI: 10.5286/isis.e.rb2010705-1
title: Neutron Diffraction Study of Perovskite Photocatalysts

description: Photocatalytic water splitting is of significant interest due to the potential utilization of renewable solar energy for production of clean and green H2 fuel. Among various metal oxide based photocatalysts, perovskite oxides are promising. In a ABO3 perovskite structure, changing stoichiometry or creating A or B site defects by incorporating cations with different valency and size facilitates interesting properties. Moreover, exsolution of light absorbing nanoparticles from the perovskite lattice can result in improved photocatalysts. The aim of this neutron diffraction study is to explore and improve understanding of the substitution and exsolution mechanism in the perovskite lattice and therefore its influence on photocatalysis can be correlated. Furthermore, this will enable us to optimize and develop a new class of photocatalyst materials with enhanced energy conversion efficiency.
DOI: 10.5286/isis.e.rb2010049
title: Oxide ion and proton dynamics in the novel ionic conductor Ba7Nb4MoO20

description: Oxide-ion and proton-conducting materials attract considerable interest thanks to their application as electrolytes in solid-oxide fuel cells (SOFCs). We have recently identified remarkable oxide ion and proton conductivity in Ba7MoNb4O20, a cation-deficient hexagonal perovskite derivative with an average crystal structure composed by palmierite-like layers alternated with hexagonal perovskite units. Ba7MoNb4O20 presents considerable local cation and anion disorder. Oxygen disorder along the palmierite-like layers leads to mixed coordination environments for Mo/Nb cations and produces pathways for ionic diffusion. Via quasielastic neutron scattering measurements as function of temperature, we aim to investigate the oxide ion and proton dynamics and gain more in-depth detail of the ionic diffusion mechanism in this fascinating novel conductor.
DOI: 10.5286/isis.e.rb2010049-1
title: Oxide ion and proton dynamics in the novel ionic conductor Ba7Nb4MoO20

description: Oxide-ion and proton-conducting materials attract considerable interest thanks to their application as electrolytes in solid-oxide fuel cells (SOFCs). We have recently identified remarkable oxide ion and proton conductivity in Ba7MoNb4O20, a cation-deficient hexagonal perovskite derivative with an average crystal structure composed by palmierite-like layers alternated with hexagonal perovskite units. Ba7MoNb4O20 presents considerable local cation and anion disorder. Oxygen disorder along the palmierite-like layers leads to mixed coordination environments for Mo/Nb cations and produces pathways for ionic diffusion. Via quasielastic neutron scattering measurements as function of temperature, we aim to investigate the oxide ion and proton dynamics and gain more in-depth detail of the ionic diffusion mechanism in this fascinating novel conductor.
DOI: 10.5286/isis.e.rb2010640
title: Metal Ions in Choline Chloride: Urea: Glycerol Ternary Deep Eutectic Solvents

description: Deep eutectic solvents (DES) are novel liquids composed of inexpensive components, and are non-flammable, with a low volatility. We wish to use the ternary choline chloride:urea:glycerol DES for the surfactant templated synthesis of metal oxide nanoparticles. Our previous experiments have shown that the successful synthesis and isolation of iron oxide nanoparticles is highly dependent on the urea:glycerol ratio within the DES, with a higher urea content being favourable. This suggests a difference in the speciation and interaction of the iron precursor with the DES, varying with the urea:glycerol content. Here, we aim to study these interactions further using neutron diffraction techniques and determine the effect of the urea:glycerol ratio on the metal ion-DES interactions. This understanding will be crucial in designing appropriate systems for templated metal oxide synthesis.
DOI: 10.5286/isis.e.rb2010640-1
title: Metal Ions in Choline Chloride: Urea: Glycerol Ternary Deep Eutectic Solvents

description: Deep eutectic solvents (DES) are novel liquids composed of inexpensive components, and are non-flammable, with a low volatility. We wish to use the ternary choline chloride:urea:glycerol DES for the surfactant templated synthesis of metal oxide nanoparticles. Our previous experiments have shown that the successful synthesis and isolation of iron oxide nanoparticles is highly dependent on the urea:glycerol ratio within the DES, with a higher urea content being favourable. This suggests a difference in the speciation and interaction of the iron precursor with the DES, varying with the urea:glycerol content. Here, we aim to study these interactions further using neutron diffraction techniques and determine the effect of the urea:glycerol ratio on the metal ion-DES interactions. This understanding will be crucial in designing appropriate systems for templated metal oxide synthesis.
DOI: 10.5286/isis.e.rb2010131
title: Topological triplon excitations in a dimerized quantum magnet.

description: Triplons are triply degenerate spin S = 1 quasiparticles corresponding to the triplet spin excitations of the singlets in a valence bond solid. There are much exotic physics associated with triplon excitations, for instance, bosonic topological insulators states, magnetization plateaus, Bose-Einstein condensation under a magnetic field or rich phase diagrams by applying an external magnetic field and so on. Thus, triplons offer a fertile ground to explore the bosonic excitations and motivate us to search for more hosting materials. In this respect, Na2Cu2TeO6 (NCTO) has come to our attention. Our previous measurements reveal that its ground state may be the singlet state with a gap around 9 meV. Beyond the ground state, the possible topological triplon excitation need to be further studied by inelastic neutron scattering experiments.
DOI: 10.5286/isis.e.rb2010131-1
title: Topological triplon excitations in a dimerized quantum magnet.

description: Triplons are triply degenerate spin S = 1 quasiparticles corresponding to the triplet spin excitations of the singlets in a valence bond solid. There are much exotic physics associated with triplon excitations, for instance, bosonic topological insulators states, magnetization plateaus, Bose-Einstein condensation under a magnetic field or rich phase diagrams by applying an external magnetic field and so on. Thus, triplons offer a fertile ground to explore the bosonic excitations and motivate us to search for more hosting materials. In this respect, Na2Cu2TeO6 (NCTO) has come to our attention. Our previous measurements reveal that its ground state may be the singlet state with a gap around 9 meV. Beyond the ground state, the possible topological triplon excitation need to be further studied by inelastic neutron scattering experiments.
DOI: 10.5286/isis.e.rb2010580
title: Probing lithium diffusion in mechanochemically-synthesised LiGaX4 (X = Cl, Br and I) and Li3MX6 (M = Y, Ho; X = Cl, Br) using muSR

description: In the current work, we study inorganic solid-state electrolytes for Li-ion batteries. These materials, unlike liquids, could lead to a breakthrough in battery lifetime and safety, since the use of flammable organic solvents is no longer needed. Our aim is to study the ways in which the ionic conductivity can be tuned and contribute to the understanding of the synthesis-structure-property relationships. We propose to perform muSR experiments on the two series of LiGaX4 (X = Cl, Br, I) and Li3MX6 (M = Y, Ho; X = Cl, Br) samples. Our interest is to asses the effect of both the mechanochemical synthesis and the varying polarizability of the anion framework (as a function of X). In order to obtain a definitive model of the crystal structure, we will also perform PND studies. These complementary studies will be of key importance to propose valid conduction mechanisms in our materials.