cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb2010751-1
title: Dynamics and local ordering in formamidinium based organic-inorganic hybrid perovskites; A parametric study

description: The interest in organic-inorganic hybrid perovskites has boomed in recent years riding off the back of the recent push beyond the 22% efficiency mark. The novelty of the system hinges upon the inclusion of an organic cation as the “A” unit of the prototypical ABX3 perovskite structure. We wish to study a series of formamidinium (FA) based variants which has received surprisingly little attention, despite initial studies showing a more complex phase behaviour, with a metastable phase at high temperature. We will employ a combined INS and ab initio approach to understand the atomistic dynamics, bonding and local ordering. We seek to explain the observed differences in phase behaviour and dielectric properties at the atomic scale, with the hope of uncovering general design principles to tailor phase behaviour and dynamics.
DOI: 10.5286/isis.e.rb1820294
title: The volume isotope effect in high-pressure ice II within its stability field

description: Water ice forms a remarkable diversity of structures, occurring in as many as 17 crystalline forms. Water ice also shows other interesting and unusual properties; e.g., solid ice Ih (as found in glaciers and in domestic freezers) is less dense than its own liquid. What is less well known is that ice Ih shows negative volume thermal expansion below ~60 K (i.e. the crystals shrink as they are heated) and an anomalous volume difference due to isotopic substitution - the molar volume of D2O is larger than that of H2O, rather than the more usual situation, whereby substitution of the heavier isotope decreases the volume. In a recent study at ISIS, we found that the isotope effect in the high-pressure form of ice called "ice II" is "normal" in samples recovered to room pressure; the aim of this proposal is to determine whether this is still true at the pressures at which ice II is stable.
DOI: 10.5286/isis.e.rb1820294-1
title: The volume isotope effect in high-pressure ice II within its stability field

description: Water ice forms a remarkable diversity of structures, occurring in as many as 17 crystalline forms. Water ice also shows other interesting and unusual properties; e.g., solid ice Ih (as found in glaciers and in domestic freezers) is less dense than its own liquid. What is less well known is that ice Ih shows negative volume thermal expansion below ~60 K (i.e. the crystals shrink as they are heated) and an anomalous volume difference due to isotopic substitution - the molar volume of D2O is larger than that of H2O, rather than the more usual situation, whereby substitution of the heavier isotope decreases the volume. In a recent study at ISIS, we found that the isotope effect in the high-pressure form of ice called "ice II" is "normal" in samples recovered to room pressure; the aim of this proposal is to determine whether this is still true at the pressures at which ice II is stable.
DOI: 10.5286/isis.e.rb1920344
title: Ground state of the layered triangular antiferromagnet YbZnGaO4

description: YbMgGaO4 and YbZnGaO4 are recently discovered triangular antiferromagnets , which contain quasi-2D layers of Yb3+ ions. These ions experience strong spin orbit coupling and have an effective spin of 1/2. YbMgGaO4 has been proposed to be the first candidate system for a quantum spin liquid state with strong spin orbit coupling and experiments indicate that it indeed remains disordered down to 60 mK, while also exhibiting antiferromagnetic correlations. However, recent theoretical calculations suggest that it in fact adapts a stripe-ordered state which mimics a spin-liquid state. YbZnGaO4 is an ideal candidate to test this scenario: it is isostructural to YbMgGaO4 but the substitution of Mg2+ with Zn2+ may reduce the effect of disorder due to the closer match of ionic radii and electronic configuration with the Ga3+ ions. Muons are ideal in probing the properties of this new material.
DOI: 10.5286/isis.e.rb1920344-1
title: Ground state of the layered triangular antiferromagnet YbZnGaO4

description: YbMgGaO4 and YbZnGaO4 are recently discovered triangular antiferromagnets , which contain quasi-2D layers of Yb3+ ions. These ions experience strong spin orbit coupling and have an effective spin of 1/2. YbMgGaO4 has been proposed to be the first candidate system for a quantum spin liquid state with strong spin orbit coupling and experiments indicate that it indeed remains disordered down to 60 mK, while also exhibiting antiferromagnetic correlations. However, recent theoretical calculations suggest that it in fact adapts a stripe-ordered state which mimics a spin-liquid state. YbZnGaO4 is an ideal candidate to test this scenario: it is isostructural to YbMgGaO4 but the substitution of Mg2+ with Zn2+ may reduce the effect of disorder due to the closer match of ionic radii and electronic configuration with the Ga3+ ions. Muons are ideal in probing the properties of this new material.
DOI: 10.5286/isis.e.rb2010139
title: Deep Inelastic Neutron Scattering study of La2LiHO3 and La2LiDO3 oxyhydrides

description: Oxyhydrides represent a new class of materials which is as yet poorly understood. The recent exciting discovery of the first purely hydride conducting oxyhydride is promising for the future of solid-state electrochemical devices, as the high redox potential of Hydride ions (-2.3 V (H-/H2)) makes them very relevant for high energy density applications. Despite proving the existence of hydride conduction within these materials, there is currently no understanding of the microscopic mechanisms for the diffusion, which is crucial for developing future devices. In this experiment we aim to measure the dissociation energy of the hydride anions in the La2LiHO3 oxyhydride. By doing so, we will gain fundamental insight to the underlying physics of oxyhydrides, which is essential to improve the functional properties of oxyhydrides if they where to be employed in future technology.
DOI: 10.5286/isis.e.rb2010139-1
title: Deep Inelastic Neutron Scattering study of La2LiHO3 and La2LiDO3 oxyhydrides

description: Oxyhydrides represent a new class of materials which is as yet poorly understood. The recent exciting discovery of the first purely hydride conducting oxyhydride is promising for the future of solid-state electrochemical devices, as the high redox potential of Hydride ions (-2.3 V (H-/H2)) makes them very relevant for high energy density applications. Despite proving the existence of hydride conduction within these materials, there is currently no understanding of the microscopic mechanisms for the diffusion, which is crucial for developing future devices. In this experiment we aim to measure the dissociation energy of the hydride anions in the La2LiHO3 oxyhydride. By doing so, we will gain fundamental insight to the underlying physics of oxyhydrides, which is essential to improve the functional properties of oxyhydrides if they where to be employed in future technology.
DOI: 10.5286/isis.e.rb2010139-2
title: Deep Inelastic Neutron Scattering study of La2LiHO3 and La2LiDO3 oxyhydrides

description: Oxyhydrides represent a new class of materials which is as yet poorly understood. The recent exciting discovery of the first purely hydride conducting oxyhydride is promising for the future of solid-state electrochemical devices, as the high redox potential of Hydride ions (-2.3 V (H-/H2)) makes them very relevant for high energy density applications. Despite proving the existence of hydride conduction within these materials, there is currently no understanding of the microscopic mechanisms for the diffusion, which is crucial for developing future devices. In this experiment we aim to measure the dissociation energy of the hydride anions in the La2LiHO3 oxyhydride. By doing so, we will gain fundamental insight to the underlying physics of oxyhydrides, which is essential to improve the functional properties of oxyhydrides if they where to be employed in future technology.
DOI: 10.5286/isis.e.rb2000177
title: Local structure in ‘disordered’ rocksalt cathode materials for Li-ion batteries

description: New families of cathode materials for Li-ion batteries, with greater capacities, are required to more effectively meet the worlds energy storage demands. Li-excess, cation disordered materials such as Li1.25Nb0.25Mn0.5O2 (LiNbMnO) have shown promise as materials with significantly higher capacities than their layered counterparts and allow for a broad compositional range. However the nature of the long- and short-range cation ordering (or disordering) within these materials is not yet well understood. In a recent publication we reported short-range order present in LiNbMnO, and with the help of neutron total scattering from Polaris we characterised the material's local structure. We have since observed a new ordering ordering regime, and so we propose to carry out high quality total neutron scattering on several further, more highly-ordered samples of LiNbMnO to finish our study.
DOI: 10.5286/isis.e.rb2000177-1
title: Local structure in ‘disordered’ rocksalt cathode materials for Li-ion batteries

description: New families of cathode materials for Li-ion batteries, with greater capacities, are required to more effectively meet the worlds energy storage demands. Li-excess, cation disordered materials such as Li1.25Nb0.25Mn0.5O2 (LiNbMnO) have shown promise as materials with significantly higher capacities than their layered counterparts and allow for a broad compositional range. However the nature of the long- and short-range cation ordering (or disordering) within these materials is not yet well understood. In a recent publication we reported short-range order present in LiNbMnO, and with the help of neutron total scattering from Polaris we characterised the material's local structure. We have since observed a new ordering ordering regime, and so we propose to carry out high quality total neutron scattering on several further, more highly-ordered samples of LiNbMnO to finish our study.
DOI: 10.5286/isis.e.rb1920536
title: Soft-templated 3D nanostructured semiconductors

description: In this experiment we will exploit the lyotropic liquid crystalline phases of non-polar surfactants and we will use them as a template for growing the semiconductors (ZnO) using electrochemical deposition. We will contrast match the template to the semiconductor and we will use SANS to find the optimum growing conditions. One of the aims of this project is the construction (by Mr. Joshua White) of an in-situ SANS cell, and this experiment will be the first step towards this objective
DOI: 10.5286/isis.e.rb1920536-1
title: Soft-templated 3D nanostructured semiconductors

description: In this experiment we will exploit the lyotropic liquid crystalline phases of non-polar surfactants and we will use them as a template for growing the semiconductors (ZnO) using electrochemical deposition. We will contrast match the template to the semiconductor and we will use SANS to find the optimum growing conditions. One of the aims of this project is the construction (by Mr. Joshua White) of an in-situ SANS cell, and this experiment will be the first step towards this objective
DOI: 10.5286/isis.e.rb2000237
title: Magnetic excitations in newly synthesized Tm2Ir2O7 pyrochlore iridate

description: The rare-earth iridates of the general formula A2Ir2O7, have been extensively studied for their frequently exotic electronic properties originating in a geometrically frustrated lattice of pyrochlore type. We have recently synthesized a large quantity (several grams) of polycrystalline heavy rare-earth A2Ir2O7 pyrochlores and investigated their low-temperature properties. To fully understand the observed electronic/magnetic properties, the microscopic studies are highly desirable. We aim to reveal the magnetic (crystal field) and lattice excitation spectra of newly synthesised Tm2Ir2O7 pyrochlore oxide and their evolutions with temperature. We propose 3 days experimental time on MARI spectrometer to investigate Tm2Ir2O7 and its 'non-magnetic' counterpart Lu2Ir2O7.
DOI: 10.5286/isis.e.rb2000237-1
title: Magnetic excitations in newly synthesized Tm2Ir2O7 pyrochlore iridate

description: The rare-earth iridates of the general formula A2Ir2O7, have been extensively studied for their frequently exotic electronic properties originating in a geometrically frustrated lattice of pyrochlore type. We have recently synthesized a large quantity (several grams) of polycrystalline heavy rare-earth A2Ir2O7 pyrochlores and investigated their low-temperature properties. To fully understand the observed electronic/magnetic properties, the microscopic studies are highly desirable. We aim to reveal the magnetic (crystal field) and lattice excitation spectra of newly synthesised Tm2Ir2O7 pyrochlore oxide and their evolutions with temperature. We propose 3 days experimental time on MARI spectrometer to investigate Tm2Ir2O7 and its 'non-magnetic' counterpart Lu2Ir2O7.
DOI: 10.5286/isis.e.rb2000259
title: Validation of a foil selector tool and novel neutron spectrum unfolding codes at ChipIR

description: Neutron spectrum unfolding is a technique that allows the energy of neutrons produced at facilities like ChipIR to be determined from indirect methods of material irradiation. The accuracy and efficacy of the unfolding technique is often highly sensitive to the materials selected for irradiation by the neutron field of interest. To optimise this process a foil selector tool has been developed as part of a joint PhD project between the UKAEA, Sheffield Hallam University and the University of Brighton. The code automates the process of foil selection and provides users with the optimal set of material samples, as well as suggestions for foil diameter and thickness, to achieve the best results when neutron spectrum unfolding is applied post-irradiation. We are looking to perform the first experimental validation of this foil selector code and the novel neutron spectrum unfolding methods.
DOI: 10.5286/isis.e.rb2000259-1
title: Validation of a foil selector tool and novel neutron spectrum unfolding codes at ChipIR

description: Neutron spectrum unfolding is a technique that allows the energy of neutrons produced at facilities like ChipIR to be determined from indirect methods of material irradiation. The accuracy and efficacy of the unfolding technique is often highly sensitive to the materials selected for irradiation by the neutron field of interest. To optimise this process a foil selector tool has been developed as part of a joint PhD project between the UKAEA, Sheffield Hallam University and the University of Brighton. The code automates the process of foil selection and provides users with the optimal set of material samples, as well as suggestions for foil diameter and thickness, to achieve the best results when neutron spectrum unfolding is applied post-irradiation. We are looking to perform the first experimental validation of this foil selector code and the novel neutron spectrum unfolding methods.
DOI: 10.5286/isis.e.rb2000259-2
title: Validation of a foil selector tool and novel neutron spectrum unfolding codes at ChipIR

description: Neutron spectrum unfolding is a technique that allows the energy of neutrons produced at facilities like ChipIR to be determined from indirect methods of material irradiation. The accuracy and efficacy of the unfolding technique is often highly sensitive to the materials selected for irradiation by the neutron field of interest. To optimise this process a foil selector tool has been developed as part of a joint PhD project between the UKAEA, Sheffield Hallam University and the University of Brighton. The code automates the process of foil selection and provides users with the optimal set of material samples, as well as suggestions for foil diameter and thickness, to achieve the best results when neutron spectrum unfolding is applied post-irradiation. We are looking to perform the first experimental validation of this foil selector code and the novel neutron spectrum unfolding methods.
DOI: 10.5286/isis.e.rb2010172
title: Analysing the magnetic disorder around ferromagnetic nanoprecipitates within an antiferromagnetic matrix

description: Ni50Mn45In5 alloy decomposes into nanosized Ni50Mn25In25 precipitates which become embedded in a Ni50Mn50 matrix when annealed at temperatures between about 650 and 750 K under a magnetic field &gt; 0.1T. The precipitates have a Curie temperature of around 320K and are ferromagnetic at room temperature, whereas the matrix is antiferromagnetic. In a previous small-angle neutron scattering (SANS) study of such a sample, we found that the ferromagnetic nanoprecipitates (which are around 55 nm in size) represent sources of perturbation, which seem to give rise to magnetically disordered regions in the vicinity of the particle-matrix interface. Here, we want to use SANS to systematically study the influence of external magnetic fields and temperature on the magnetically disordered regions around the nanoprecipitates.
DOI: 10.5286/isis.e.rb2010172-1
title: Analysing the magnetic disorder around ferromagnetic nanoprecipitates within an antiferromagnetic matrix

description: Ni50Mn45In5 alloy decomposes into nanosized Ni50Mn25In25 precipitates which become embedded in a Ni50Mn50 matrix when annealed at temperatures between about 650 and 750 K under a magnetic field &gt; 0.1T. The precipitates have a Curie temperature of around 320K and are ferromagnetic at room temperature, whereas the matrix is antiferromagnetic. In a previous small-angle neutron scattering (SANS) study of such a sample, we found that the ferromagnetic nanoprecipitates (which are around 55 nm in size) represent sources of perturbation, which seem to give rise to magnetically disordered regions in the vicinity of the particle-matrix interface. Here, we want to use SANS to systematically study the influence of external magnetic fields and temperature on the magnetically disordered regions around the nanoprecipitates.
DOI: 10.5286/isis.e.rb2010172-2
title: Analysing the magnetic disorder around ferromagnetic nanoprecipitates within an antiferromagnetic matrix

description: Ni50Mn45In5 alloy decomposes into nanosized Ni50Mn25In25 precipitates which become embedded in a Ni50Mn50 matrix when annealed at temperatures between about 650 and 750 K under a magnetic field &gt; 0.1T. The precipitates have a Curie temperature of around 320K and are ferromagnetic at room temperature, whereas the matrix is antiferromagnetic. In a previous small-angle neutron scattering (SANS) study of such a sample, we found that the ferromagnetic nanoprecipitates (which are around 55 nm in size) represent sources of perturbation, which seem to give rise to magnetically disordered regions in the vicinity of the particle-matrix interface. Here, we want to use SANS to systematically study the influence of external magnetic fields and temperature on the magnetically disordered regions around the nanoprecipitates.
DOI: 10.5286/isis.e.rb2010570
title: Interaction of membrane-penetrating peptides with lipid monolayers at the air-water interface as a model for placental drug delivery

description: Placental drug delivery is an emerging and important field because there are currently no treatments for serious pregnancy complications, e.g. preeclampsia. The membrane penetrating peptides CGKRK and RSGVAKS have been shown to be internalised spontaneously not only into placental cells but also breast cancer cells. To complement our in vitro work, we have characterised using surface pressure and ellipsometry interactions of these peptides with lipid-based model membranes that mimic simplified placental and cancer cells. In this proposal we aim to resolve the extent of interaction, degree of hydration and crucially the location of binding of the peptides in model membranes using neutron reflectometry. This information will provide insight into the commonality of peptide interactions with placental and cancer cells, and help us work towards novel drug delivery strategies to the placenta.
DOI: 10.5286/isis.e.rb2010570-1
title: Interaction of membrane-penetrating peptides with lipid monolayers at the air-water interface as a model for placental drug delivery

description: Placental drug delivery is an emerging and important field because there are currently no treatments for serious pregnancy complications, e.g. preeclampsia. The membrane penetrating peptides CGKRK and RSGVAKS have been shown to be internalised spontaneously not only into placental cells but also breast cancer cells. To complement our in vitro work, we have characterised using surface pressure and ellipsometry interactions of these peptides with lipid-based model membranes that mimic simplified placental and cancer cells. In this proposal we aim to resolve the extent of interaction, degree of hydration and crucially the location of binding of the peptides in model membranes using neutron reflectometry. This information will provide insight into the commonality of peptide interactions with placental and cancer cells, and help us work towards novel drug delivery strategies to the placenta.
DOI: 10.5286/isis.e.rb1920187
title: Probing the origin of the superconducting spin-valve effect

description: Inter-layer magnetic exchange coupling is the key control mechanism underpinning spintronics and is often coupled to other spintronic effects, such as giantmagnetoresistance(GMR) and spin transfer torques. Recently, Zhu et al. reported a new class of inter-layer exchange coupling, a kind of RKKY coupling through a superconducting spin-valve structure. They observed a GMR-like response with an infinite MR ratio because of the zero resistance in the superconducting state. One of the conclusions presented in the paper is: 'the behaviour reported here cannot be explained on the basis of any conventional exchange coupling'. With our PNR+PA measurements we were able to gain a detailed understanding of the magnetic state in the superconducting phase but to clarify the influence of the superconductor itself a scan through the superconducting transition is essential.
DOI: 10.5286/isis.e.rb1920187-1
title: Probing the origin of the superconducting spin-valve effect

description: Inter-layer magnetic exchange coupling is the key control mechanism underpinning spintronics and is often coupled to other spintronic effects, such as giantmagnetoresistance(GMR) and spin transfer torques. Recently, Zhu et al. reported a new class of inter-layer exchange coupling, a kind of RKKY coupling through a superconducting spin-valve structure. They observed a GMR-like response with an infinite MR ratio because of the zero resistance in the superconducting state. One of the conclusions presented in the paper is: 'the behaviour reported here cannot be explained on the basis of any conventional exchange coupling'. With our PNR+PA measurements we were able to gain a detailed understanding of the magnetic state in the superconducting phase but to clarify the influence of the superconductor itself a scan through the superconducting transition is essential.
DOI: 10.5286/isis.e.rb2010252
title: Kinetics of the formation of large anisotropic zirconia particles followed by combined SANS/SEMSANS

description: This proposal aims to investigate the formation mechanism of anisotropic zirconia micron-sized particles, formed in solution by mixing a surfactant and the zirconia precursor; in order to better understand the role of the surfactant and be able to do rational design. Effect of the type of surfactant, temperature, and reactants quantities will be studied. The combined SANS/SEMSANS setup available in Larmor will allow us probing simultaneously the interactions between surfactant and zirconia species in solution at the nm-scale, and the growth of the particles at the µm-scale.