cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1920614
title: The Evolution of the Antiferromagnetic Order with Hole Doping of La2-xSrxCoO4.

description: Many believe that the magnetic excitations of cuprate high temperature superconductors play an important role in the material's superconductivity. Understanding the magnetic excitation spectrum of La2-xSrxCoO4 could provide a breakthrough in understanding cuprate superconductors, as both materials have very similar magnetic excitations. The electric charges that are doped into the Co-O layers La2-xSrxCoO4 by replacing La with Sr, either form regularly spaced lines; charge-stripes, or a pattern like a chess/checkerboard; checkerboard order. There are insufficient charges doped into the material to form these charge orders, leaving pockets of the material that should be equivalent to undoped La2CoO4, however an energy gap seen in the magnetic excitations of La2CoO4 is not observed. We will study the magnetic excitations at very low doping to see how this energy gap evolves with doping.
DOI: 10.5286/isis.e.rb1920614-1
title: The Evolution of the Antiferromagnetic Order with Hole Doping of La2-xSrxCoO4.

description: Many believe that the magnetic excitations of cuprate high temperature superconductors play an important role in the material's superconductivity. Understanding the magnetic excitation spectrum of La2-xSrxCoO4 could provide a breakthrough in understanding cuprate superconductors, as both materials have very similar magnetic excitations. The electric charges that are doped into the Co-O layers La2-xSrxCoO4 by replacing La with Sr, either form regularly spaced lines; charge-stripes, or a pattern like a chess/checkerboard; checkerboard order. There are insufficient charges doped into the material to form these charge orders, leaving pockets of the material that should be equivalent to undoped La2CoO4, however an energy gap seen in the magnetic excitations of La2CoO4 is not observed. We will study the magnetic excitations at very low doping to see how this energy gap evolves with doping.
DOI: 10.5286/isis.e.rb1920208
title: Total Neutron Scattering Measurements of Supercritical CO2 Injection in Carbonate Rock: Monitoring the Oil Recovery at the Nanoscale

description: Carbon dioxide is a commonly used fluid in Enhanced Oil Recovery (EOR). CO2 EOR process can contribute to the minimisation of the impact of greenhouse gas emission by keeping CO2 out of the atmosphere, as much of it is exchanged with the displaced oil in the pores, and remains trapped in the deep rock formations. We propose to utilise neutron scattering in order to monitor, for first time, the CO2 EOR process by the injection of supercritical CO2 at carbonate samples saturated with crude oil. Mapping the phase behavior of the confined mixture during CO2 injection and the displacement of oil from the pores will shed light about the process at the nanoscale level as it will be linked to the molecular order of the confined fluid mixture. The obtained information will be valuable for the optimization of the oil recovery and the development of appropriate additives for further improvement.
DOI: 10.5286/isis.e.rb1920208-1
title: Total Neutron Scattering Measurements of Supercritical CO2 Injection in Carbonate Rock: Monitoring the Oil Recovery at the Nanoscale

description: Carbon dioxide is a commonly used fluid in Enhanced Oil Recovery (EOR). CO2 EOR process can contribute to the minimisation of the impact of greenhouse gas emission by keeping CO2 out of the atmosphere, as much of it is exchanged with the displaced oil in the pores, and remains trapped in the deep rock formations. We propose to utilise neutron scattering in order to monitor, for first time, the CO2 EOR process by the injection of supercritical CO2 at carbonate samples saturated with crude oil. Mapping the phase behavior of the confined mixture during CO2 injection and the displacement of oil from the pores will shed light about the process at the nanoscale level as it will be linked to the molecular order of the confined fluid mixture. The obtained information will be valuable for the optimization of the oil recovery and the development of appropriate additives for further improvement.
DOI: 10.5286/isis.e.rb1920246
title: In situ Neutron Diffraction Study on the Effect of Annealing Treatment on Phase Analysis of Nitinol during Thermal and Mechanical Cycling

description: Nitinol (nickel-titanium alloy), which belongs to one of categories of shape memory alloy, has drawn significant attention from scientific community and industry for their wide applications in medical (blood vessel stents) and aerospace (satelllite and jet engine). Nitinol can repeatedly recover large strains (over 8%) through phase transformation. Of interest of this proposal is to investigate annealing effect on phase tranformation during both thermal and mechanical cycling of Nitinol wire, thus filling the gap in existing knowledge. The reserach out come will substantially improve the performance of shape memory alloy actuators in broad applications and bring impact to industry.
DOI: 10.5286/isis.e.rb1920246-1
title: In situ Neutron Diffraction Study on the Effect of Annealing Treatment on Phase Analysis of Nitinol during Thermal and Mechanical Cycling

description: Nitinol (nickel-titanium alloy), which belongs to one of categories of shape memory alloy, has drawn significant attention from scientific community and industry for their wide applications in medical (blood vessel stents) and aerospace (satelllite and jet engine). Nitinol can repeatedly recover large strains (over 8%) through phase transformation. Of interest of this proposal is to investigate annealing effect on phase tranformation during both thermal and mechanical cycling of Nitinol wire, thus filling the gap in existing knowledge. The reserach out come will substantially improve the performance of shape memory alloy actuators in broad applications and bring impact to industry.
DOI: 10.5286/isis.e.rb1920370-2
title: Search for magnon-phonon coupling effect in metallic triangular antiferromagnet CrB2

description: Spin dynamics of non-collinear magnetic structures can exhibit the rare phenomena which go beyond the linear spin wave theory. Our previous studies on non-collinear antiferromagnetic insulators (Y, Lu)MnO3 at ISIS showed that magnon-magnon/phonon interactions indeed have a sizable effect on the spin dynamics. To extend this concept to metallic systems, we have recently carried out an inelastic neutron scattering experiment at MAPS on CrB2, a metallic triangular antiferromagnet with non-collinear magnetic structure. Along with successful measurements of magnons over a large momentum-energy space, we observed that some phonon modes near the magnon modes have unusual behavior, which is also seen in (Y, Lu)MnO3. To confirm that this anomaly comes from magnon-phonon coupling, we propose to investigate the phonon spectra of CrB2 at 150 K, the temperature above TN =88 K where magnons disappear.
DOI: 10.5286/isis.e.rb1920370-3
title: Search for magnon-phonon coupling effect in metallic triangular antiferromagnet CrB2

description: Spin dynamics of non-collinear magnetic structures can exhibit the rare phenomena which go beyond the linear spin wave theory. Our previous studies on non-collinear antiferromagnetic insulators (Y, Lu)MnO3 at ISIS showed that magnon-magnon/phonon interactions indeed have a sizable effect on the spin dynamics. To extend this concept to metallic systems, we have recently carried out an inelastic neutron scattering experiment at MAPS on CrB2, a metallic triangular antiferromagnet with non-collinear magnetic structure. Along with successful measurements of magnons over a large momentum-energy space, we observed that some phonon modes near the magnon modes have unusual behavior, which is also seen in (Y, Lu)MnO3. To confirm that this anomaly comes from magnon-phonon coupling, we propose to investigate the phonon spectra of CrB2 at 150 K, the temperature above TN =88 K where magnons disappear.
DOI: 10.5286/isis.e.rb1920500
title: Solubilization properties of block copolymer micelles and their micellar interpolyelectrolyte complexes (IPECs).

description: Combination of ionic copolymer micelles with oppositely charged polyelectrolytes leads to the formation of interpolyelectrolyte complexes (IPECs). The aggregate has an onion- like structure, consisting of three parts: a hydrophobic core, an IPEC shell and a corona. The sizes of all parts can be tuned and controlled independently. Domains of different polarity make IPECs extremely interesting delivery systems, which can be used e.g. in drug-delivery.The aim of the proposed experiment is, first, to investigate in thorough detail the structural changes (swelling/growth and shape) of copolymer micelles induced by the solubilisation process within aqueous media and to link the solubilisation capacity to the core design and hydrophobicity of the produced systems. Aimed solubilisates are oils, deuterated oils and a cancer drug. As an exploratory study also some of the IPECs shall be studied.
DOI: 10.5286/isis.e.rb1920500-1
title: Solubilization properties of block copolymer micelles and their micellar interpolyelectrolyte complexes (IPECs).

description: Combination of ionic copolymer micelles with oppositely charged polyelectrolytes leads to the formation of interpolyelectrolyte complexes (IPECs). The aggregate has an onion- like structure, consisting of three parts: a hydrophobic core, an IPEC shell and a corona. The sizes of all parts can be tuned and controlled independently. Domains of different polarity make IPECs extremely interesting delivery systems, which can be used e.g. in drug-delivery.The aim of the proposed experiment is, first, to investigate in thorough detail the structural changes (swelling/growth and shape) of copolymer micelles induced by the solubilisation process within aqueous media and to link the solubilisation capacity to the core design and hydrophobicity of the produced systems. Aimed solubilisates are oils, deuterated oils and a cancer drug. As an exploratory study also some of the IPECs shall be studied.
DOI: 10.5286/isis.e.rb1920316
title: Evolution of magnetic excitations in FeSe1-xSx across the nematic critical point

description: The evolution of magnetism, nematic order and superconductivity in the multi-degree-of-freedom system is one of the theme issues in the study of iron-based superconductors. As the structurally simplest system, FeSe has distinct phase relations with iron pnictides under hydrostatic pressure and has raised significant interests. Isovalent S substitution introduces "chemical pressure", expands the band widths and reduces the electronic correlations. It completely suppresses the nematic order of FeSe at around 17% S doping level and tunes the superconducting pairing states. Thus it offers a good platform to study the interplay between electronic correlation, magnetism, nematicity and superconductivity. Here we propose to investigate the evolution of the magnetic excitation across the nematic critical point, via inelastic neutron scattering on FeSe0.9S0.1 and FeSe0.8S0.2
DOI: 10.5286/isis.e.rb1920316-1
title: Evolution of magnetic excitations in FeSe1-xSx across the nematic critical point

description: The evolution of magnetism, nematic order and superconductivity in the multi-degree-of-freedom system is one of the theme issues in the study of iron-based superconductors. As the structurally simplest system, FeSe has distinct phase relations with iron pnictides under hydrostatic pressure and has raised significant interests. Isovalent S substitution introduces "chemical pressure", expands the band widths and reduces the electronic correlations. It completely suppresses the nematic order of FeSe at around 17% S doping level and tunes the superconducting pairing states. Thus it offers a good platform to study the interplay between electronic correlation, magnetism, nematicity and superconductivity. Here we propose to investigate the evolution of the magnetic excitation across the nematic critical point, via inelastic neutron scattering on FeSe0.9S0.1 and FeSe0.8S0.2
DOI: 10.5286/isis.e.rb1920495
title: Field-induced low-temperature magnetic phase in alkali-metal sesquioxides

description: Open p-shell anionic compounds are model systems where the interplay between charge, lattice, orbital, and spin degrees of freedom leads to complex magnetic behavior. In the superoxide NaO2 and the mixed valence sesquioxide Rb4O6, both featuring O2- entities with spin S=1/2 and low-dimensional (D) magnetism, we have recently observed by muSR an unconventional field-induced static magnetic phase out of a dynamical magnetic zero-field ground state. Several questions emerged from these studies, e.g., whether the field-induced phase is generally intrinsic to O2- molecules, whether charge ordering plays a role and whether low-D cooperative magnetism due to orbital order is required to induce it. To address these questions we propose a muSR study of both, the tetragonal and the quenched cubic phases of Rb4O6 and Cs4O6. Contrary to Rb4O6, Cs4O6 reveals charge ordering but no low-D magnetism.
DOI: 10.5286/isis.e.rb1920495-1
title: Field-induced low-temperature magnetic phase in alkali-metal sesquioxides

description: Open p-shell anionic compounds are model systems where the interplay between charge, lattice, orbital, and spin degrees of freedom leads to complex magnetic behavior. In the superoxide NaO2 and the mixed valence sesquioxide Rb4O6, both featuring O2- entities with spin S=1/2 and low-dimensional (D) magnetism, we have recently observed by muSR an unconventional field-induced static magnetic phase out of a dynamical magnetic zero-field ground state. Several questions emerged from these studies, e.g., whether the field-induced phase is generally intrinsic to O2- molecules, whether charge ordering plays a role and whether low-D cooperative magnetism due to orbital order is required to induce it. To address these questions we propose a muSR study of both, the tetragonal and the quenched cubic phases of Rb4O6 and Cs4O6. Contrary to Rb4O6, Cs4O6 reveals charge ordering but no low-D magnetism.
DOI: 10.5286/isis.e.rb1920516
title: Dynamics of Protein-Confined Water in Polymer Vesicles: A Feasibility Study

description: When we confine water in extremely small spaces it starts to move extremely slowly. This behaviour is critical to helping biological molecules like proteins function normally. We have developed a system in which we can place very large amounts of protein in hollow containers called vesicles, which can be as small as 50 nanometres. When we encapsulate special types of proteins called enzymes, which help the body perform chemical reactions, we find the enzymes work faster when they're inside the vesicles than they do when they're outside it. Even more remarkably, we find that when we heat up our vesicles, enzymes inside the vesicles continue to work at temperatures that would normally break them. We think we can explain our findings by studying how changing the amount of protein in a vesicle changes the way the water inside the vesicle moves.
DOI: 10.5286/isis.e.rb1920516-1
title: Dynamics of Protein-Confined Water in Polymer Vesicles: A Feasibility Study

description: When we confine water in extremely small spaces it starts to move extremely slowly. This behaviour is critical to helping biological molecules like proteins function normally. We have developed a system in which we can place very large amounts of protein in hollow containers called vesicles, which can be as small as 50 nanometres. When we encapsulate special types of proteins called enzymes, which help the body perform chemical reactions, we find the enzymes work faster when they're inside the vesicles than they do when they're outside it. Even more remarkably, we find that when we heat up our vesicles, enzymes inside the vesicles continue to work at temperatures that would normally break them. We think we can explain our findings by studying how changing the amount of protein in a vesicle changes the way the water inside the vesicle moves.
DOI: 10.5286/isis.e.rb1968028
title: Avalanche-like hybrid-improper ferroelectric transition in SrBi2Nb2O9

description: Improper-ferroelectrics (FE) are the backbone to development towards room-temperature multiferroics and carry the immense technological potential for next-generation data-storage and energy conversion. This class of FEs differs from displacive FEs (i.e. BaTiO3) as ferroelectricity is induced by anharmonic coupling between a (multiple) non-polar and a polar mode. With the proposed work, we aim to measure the condensation of non-polar and polar modes and confirm the theoretically proposed transition path. These polar and non-polar modes involve motions of heavy (Bi) and light (O) atoms, consequently, their energy scales are vastly different allowing for separation of dynamics on powder samples. Detailed T-dependent phonon measurements will also enable us to probe unusual T-dependence of polarization, which deviates strongly from square-root law because of the anharmonic coupling.
DOI: 10.5286/isis.e.rb1920197
title: Structure and synthesis optimisation of BSCFW, a self-assembled dynamic perovskite composite cathode for intermediate temperature SOFCs

description: The performance of new state-of-the-art Ba0.5Sr0.5(Co0.7Fe0.3)0.6875W0.3125O3-d (BSCFW) cathode materials for solid oxide fuel cells, which are composites of single- (SP) and double- perovskite (DP) phases we published recently, is highly correlated to the preparation route and processing conditions. This is mediated by the interplay between the separate phases through lattice mismatch and ability for the exchange of W6+ from DP to SP at operating conditions, significantly enhancing material stability. Using high-resolution neutron diffraction, we aim to understand the subtle structural differences induced through different preparative conditions in these materials. This knowledge will inform future processing routes to such materials as part of our current collaboration with industry for industrial-scale testing.
DOI: 10.5286/isis.e.rb1920197-1
title: Structure and synthesis optimisation of BSCFW, a self-assembled dynamic perovskite composite cathode for intermediate temperature SOFCs

description: The performance of new state-of-the-art Ba0.5Sr0.5(Co0.7Fe0.3)0.6875W0.3125O3-d (BSCFW) cathode materials for solid oxide fuel cells, which are composites of single- (SP) and double- perovskite (DP) phases we published recently, is highly correlated to the preparation route and processing conditions. This is mediated by the interplay between the separate phases through lattice mismatch and ability for the exchange of W6+ from DP to SP at operating conditions, significantly enhancing material stability. Using high-resolution neutron diffraction, we aim to understand the subtle structural differences induced through different preparative conditions in these materials. This knowledge will inform future processing routes to such materials as part of our current collaboration with industry for industrial-scale testing.
DOI: 10.5286/isis.e.rb1920405
title: Crystal-field and magnetic excitations in NdTa7O19

description: Rare-earth based geometrically frustrated magnets represent a promising new platform of searching for enigmatic quantum states of matter. Here, entanglement of spin and orbital degrees of freedom is believed to be one of the crucial factors that can stabilize disordered, yet highly quantum-entangled ground state. In our study, we focus on a novel rare-earth based triangular-lattice antiferromagnet NdTa7O19, where such effects might take place. Our previous measurement have demonstrated that magnetic order is absent in this material at least down to 66 mK. However, nothing is known about its low-lying excitations, which can be most conveniently revealed by inelastic neutron scattering. Such excitations may include those from crystal-field levels, the knowledge of which is essential for successful modelling of the magnetism in the investigated compound.
DOI: 10.5286/isis.e.rb1920405-1
title: Crystal-field and magnetic excitations in NdTa7O19

description: Rare-earth based geometrically frustrated magnets represent a promising new platform of searching for enigmatic quantum states of matter. Here, entanglement of spin and orbital degrees of freedom is believed to be one of the crucial factors that can stabilize disordered, yet highly quantum-entangled ground state. In our study, we focus on a novel rare-earth based triangular-lattice antiferromagnet NdTa7O19, where such effects might take place. Our previous measurement have demonstrated that magnetic order is absent in this material at least down to 66 mK. However, nothing is known about its low-lying excitations, which can be most conveniently revealed by inelastic neutron scattering. Such excitations may include those from crystal-field levels, the knowledge of which is essential for successful modelling of the magnetism in the investigated compound.
DOI: 10.5286/isis.e.rb1920499
title: Exploration of possible spin-charge ordered phases in La2-xBaxCoO4 (x=1/3 and 1/2)

description: This is a proposal to measure the magnetic spectrum of single crystal La2-xBaxCoO4 for the first time. The isostructural layered cobaltates with Sr and Ca instead of Ba have been studied extensively. The x=1/2 composition exhibits long-range checkerboard charge order and accompanying antiferromagnetic order, but the x = 1/3 composition is more complex. It has a nanoscale coexistence of different electronic phases, including period-3 spin-charge stripes, and has a distinctive hourglass-shaped magnetic spectrum. The Ba-doped system has not been investigated previously. Our objective is to obtain a complete mapping in energy and momentum of the magnetic spectrum of La2-xBaxCoO4 with x = 1/3 and 1/2. The results will be compared with the known spectra of La2-xSrxCoO4, and by analysing the spectra quantitatively we hope to gain a picture of the electronic ground state in these systems.
DOI: 10.5286/isis.e.rb1968028-1
title: Avalanche-like hybrid-improper ferroelectric transition in SrBi2Nb2O9

description: Improper-ferroelectrics (FE) are the backbone to development towards room-temperature multiferroics and carry the immense technological potential for next-generation data-storage and energy conversion. This class of FEs differs from displacive FEs (i.e. BaTiO3) as ferroelectricity is induced by anharmonic coupling between a (multiple) non-polar and a polar mode. With the proposed work, we aim to measure the condensation of non-polar and polar modes and confirm the theoretically proposed transition path. These polar and non-polar modes involve motions of heavy (Bi) and light (O) atoms, consequently, their energy scales are vastly different allowing for separation of dynamics on powder samples. Detailed T-dependent phonon measurements will also enable us to probe unusual T-dependence of polarization, which deviates strongly from square-root law because of the anharmonic coupling.
DOI: 10.5286/isis.e.rb1968028-2
title: Avalanche-like hybrid-improper ferroelectric transition in SrBi2Nb2O9

description: Improper-ferroelectrics (FE) are the backbone to development towards room-temperature multiferroics and carry the immense technological potential for next-generation data-storage and energy conversion. This class of FEs differs from displacive FEs (i.e. BaTiO3) as ferroelectricity is induced by anharmonic coupling between a (multiple) non-polar and a polar mode. With the proposed work, we aim to measure the condensation of non-polar and polar modes and confirm the theoretically proposed transition path. These polar and non-polar modes involve motions of heavy (Bi) and light (O) atoms, consequently, their energy scales are vastly different allowing for separation of dynamics on powder samples. Detailed T-dependent phonon measurements will also enable us to probe unusual T-dependence of polarization, which deviates strongly from square-root law because of the anharmonic coupling.