cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1920572-1
title: Quasi-Elastic Neutron Scattering on adenine-based gold(I) hydrogel-entangled water molecules

description: The hydrogelation of gold(I) complexes is a fascinating albeit still underdeveloped area of soft matter chemistry, with feasible high-technology applications based on the unique properties of this metal. Although the scarce number of reported examples so far has been thoroughly studied by a wide plethora of techniques, there is a general lack of information on how water molecules assist the formation of the supramolecular hydrogelating motifs (which are commonly fibers). Herein, we propose the in-depth study of the dynamical behaviour of water and the hydrogel matrix in three of adenine-based gold(I) low molecular weight hydrometallogelators, by quasi-elastic neutron scattering (QENS).
DOI: 10.5286/isis.e.rb1920748
title: Relaxation plateau in the breathing pyrochlore antiferromagnet LiIn0.05Ga0.95Cr4O8

description: In physics, frustration describes a situation where a system is unable to satisfy all of its internal interactions because of the geometry of its atomic structure. The most studied examples of frustration are magnetic systems containing triangular motifs; in these, conventional magnetism is often suppressed in favour of new, exotic states of magnetic matter. One such state has recently been observed for the first time in LiIn0.05Ga0.95Cr4O8, a material where the magnetic chromium ions form a lattice of tetrahedra. Below a temperature of 12 K, the magnetic moments suddenly become collinear without simultaneously ordering; this behaviour is similar to that of liquid crystals in display screens. It turns out that the interactions which generate the transition are also expected to support an unusual type of spin dynamics. It is these that we are aiming to observe with the proposed experiment
DOI: 10.5286/isis.e.rb1920748-1
title: Relaxation plateau in the breathing pyrochlore antiferromagnet LiIn0.05Ga0.95Cr4O8

description: In physics, frustration describes a situation where a system is unable to satisfy all of its internal interactions because of the geometry of its atomic structure. The most studied examples of frustration are magnetic systems containing triangular motifs; in these, conventional magnetism is often suppressed in favour of new, exotic states of magnetic matter. One such state has recently been observed for the first time in LiIn0.05Ga0.95Cr4O8, a material where the magnetic chromium ions form a lattice of tetrahedra. Below a temperature of 12 K, the magnetic moments suddenly become collinear without simultaneously ordering; this behaviour is similar to that of liquid crystals in display screens. It turns out that the interactions which generate the transition are also expected to support an unusual type of spin dynamics. It is these that we are aiming to observe with the proposed experiment
DOI: 10.5286/isis.e.rb1920038
title: When like-charged ions attract: How OH-defects influence the size and distribution of cationic clusters in ionic liquids

description: This study will probe the liquid nanostructures of mixtures of two ionic liquids, 4-(hydroxybutyl)-pyridinium-bis(trifluorosulfonyl)-imide ([HOC4Py]NTf2) and pentylpyridinium-bis(trifluorosulfonyl)-imide ([C5Py]NTf2), which are identical except that the alkyl chain of the former is terminated by OH and the latter by CH3. Hence, ion clustering is expected in [HOC4Py]NTf2 but not in [C5Py]NTf2, which will reveal the effect of the alcohol H-bonding unambiguously. We will determine how the defects of OH groups in the H-bond network will influence the cluster distribution and the most probable cluster structures. Furthermore, we will figure out how big the anion excess has to be to break down the bigger cation-cation-based aggregates into cation-anion monomers.
DOI: 10.5286/isis.e.rb1920038-1
title: When like-charged ions attract: How OH-defects influence the size and distribution of cationic clusters in ionic liquids

description: This study will probe the liquid nanostructures of mixtures of two ionic liquids, 4-(hydroxybutyl)-pyridinium-bis(trifluorosulfonyl)-imide ([HOC4Py]NTf2) and pentylpyridinium-bis(trifluorosulfonyl)-imide ([C5Py]NTf2), which are identical except that the alkyl chain of the former is terminated by OH and the latter by CH3. Hence, ion clustering is expected in [HOC4Py]NTf2 but not in [C5Py]NTf2, which will reveal the effect of the alcohol H-bonding unambiguously. We will determine how the defects of OH groups in the H-bond network will influence the cluster distribution and the most probable cluster structures. Furthermore, we will figure out how big the anion excess has to be to break down the bigger cation-cation-based aggregates into cation-anion monomers.
DOI: 10.5286/isis.e.rb1920064
title: Excitation Spectrum of the Topological Spin Order in SrFeO3

description: Spin dynamics in multi-q noncoplanar ordered structures (e.g. skyrmion lattices) is an active topic of research. The cubic perovskite SrFeO3 has a variety of multiple-q magnetic phases including a recently identified 3D topological spin order that is analogous to a skyrmion lattice. This highly symmetric noncoplanar phase on a cubic lattice is characterized by a star of 4 equivalent magnetic propagation vectors pointing along the {111} cubic directions. In contrast to the less symmetric ground-state phase, which forms multiple magnetic domains, the quadruple-q phase does not suffer from magnetic twinning and should result in cleaner inelastic spectra. Here we propose to map out spin-wave excitations in SrFeO3 across the magnetic phase transitions between zero-field phases I, II, and III. The results will help us understand and model the dynamics of topological spin structures.
DOI: 10.5286/isis.e.rb1920064-1
title: Excitation Spectrum of the Topological Spin Order in SrFeO3

description: Spin dynamics in multi-q noncoplanar ordered structures (e.g. skyrmion lattices) is an active topic of research. The cubic perovskite SrFeO3 has a variety of multiple-q magnetic phases including a recently identified 3D topological spin order that is analogous to a skyrmion lattice. This highly symmetric noncoplanar phase on a cubic lattice is characterized by a star of 4 equivalent magnetic propagation vectors pointing along the {111} cubic directions. In contrast to the less symmetric ground-state phase, which forms multiple magnetic domains, the quadruple-q phase does not suffer from magnetic twinning and should result in cleaner inelastic spectra. Here we propose to map out spin-wave excitations in SrFeO3 across the magnetic phase transitions between zero-field phases I, II, and III. The results will help us understand and model the dynamics of topological spin structures.
DOI: 10.5286/isis.e.rb1920064-2
title: Excitation Spectrum of the Topological Spin Order in SrFeO3

description: Spin dynamics in multi-q noncoplanar ordered structures (e.g. skyrmion lattices) is an active topic of research. The cubic perovskite SrFeO3 has a variety of multiple-q magnetic phases including a recently identified 3D topological spin order that is analogous to a skyrmion lattice. This highly symmetric noncoplanar phase on a cubic lattice is characterized by a star of 4 equivalent magnetic propagation vectors pointing along the {111} cubic directions. In contrast to the less symmetric ground-state phase, which forms multiple magnetic domains, the quadruple-q phase does not suffer from magnetic twinning and should result in cleaner inelastic spectra. Here we propose to map out spin-wave excitations in SrFeO3 across the magnetic phase transitions between zero-field phases I, II, and III. The results will help us understand and model the dynamics of topological spin structures.
DOI: 10.5286/isis.e.rb1920124-1
title: Investigation of single ion crystal field anisotropy in heavy fermion compounds CeIr3B2 and PrIr3B2

description: The ferromagnetic transition Tc=41 K of CeIr3B2 is the second highest Tc recorded after CeRh3B2 in among Ce-based compounds makes it an interesting candidate to investigate using inelastic neutron scattering (INS). The isostructural PrIr3B2 compound also exhibits magnetic ordering at TN=10 K in addition to expected structural transition at 280 K. The susceptibility of these compounds exhibits considerable strong anisotropy. Interestingly the susceptibility of CeIr3B2 reveals a crossover behavior at high temperature (250 K) from easy ab-plane to hard c-axis. Therefore, the detailed study of crystal field excitations (CEF) using INS on MERLIN is proposed to explore the role of CEF anisotropy on the magnetic ground state. This study will be helpful to explain the role of CEF anisotropy in the observed behavior of the magnetic susceptibility and will shed light on the crossover behavior.
DOI: 10.5286/isis.e.rb1920162
title: Exploring CO2-philic/ CO2-phobic amphiphiles, cross-linkers and HC-polymers for 3D-structured rod-like aggregates in supercritical CO2

description: Over the last two decades, many polymers have been tested to increase CO2 viscosity for applications in enhanced oil recovery using CO2 (CO2-EOR). Unfortunately, conventional HC-polymers were inactive for viscosity enhancements due to their poor solubility in supercritical CO2 (scCO2). Recent SANS studies (RB1720361, RB1820137) found that tailor-made CO2-philic/ CO2-phobic amphiphiles formed rod-like aggregates (RAs) encapsulating HC-polymers in scCO2. The length of RAs was strongly dependent on both the architectures and concentrations of the amphiphiles and HC-polymers. To develop inexpensive, environmental-friendly and effective HC-polymer-based CO2-thickners for CO2-EOR, this experiment will explore optimum structures, concentrations, and compositions of amphiphiles, cross-linkers and HC-polymers to generate 3D-structured networks of RAs with HC-polymer backbones in scCO2.
DOI: 10.5286/isis.e.rb1920474
title: From small compositional changes to large distortions - a new relaxor energy-storage material from BaTiO3 complexed with Bi2(Nb2/3Zn1/3)2O7

description: [BiZn2/3NbO3]x-[BaTiO3]1-x for x up to roughly 0.2, known as BZN-BT is a complex made from one of the most studied materials in the world, BaTiO3 (BT), doped with Bismuth Zinc Niobate (BZN) pyrochlore. Intriguingly, the addition of only 4% of BZN to BT completely changes both its crystal structure and its physical properties. Our initial experiments with x-ray diffraction in the home lab indicate the BZN doping transforms the BT to a structure it doesn't normally achieve until 250K. Then that further doping up to 0.1 produces a phase that looks as though it is the most symmetrical possible (cubic) but still possessing physical properties such as piezoelectricity, which is contradictory. Finally, the behaviour with decreasing temperature is altered from that of BT itself so that we have a new sequence of phase transitions and properties to investigate from a structural point of view.
DOI: 10.5286/isis.e.rb1920474-1
title: From small compositional changes to large distortions - a new relaxor energy-storage material from BaTiO3 complexed with Bi2(Nb2/3Zn1/3)2O7

description: [BiZn2/3NbO3]x-[BaTiO3]1-x for x up to roughly 0.2, known as BZN-BT is a complex made from one of the most studied materials in the world, BaTiO3 (BT), doped with Bismuth Zinc Niobate (BZN) pyrochlore. Intriguingly, the addition of only 4% of BZN to BT completely changes both its crystal structure and its physical properties. Our initial experiments with x-ray diffraction in the home lab indicate the BZN doping transforms the BT to a structure it doesn't normally achieve until 250K. Then that further doping up to 0.1 produces a phase that looks as though it is the most symmetrical possible (cubic) but still possessing physical properties such as piezoelectricity, which is contradictory. Finally, the behaviour with decreasing temperature is altered from that of BT itself so that we have a new sequence of phase transitions and properties to investigate from a structural point of view.
DOI: 10.5286/isis.e.rb1920162-1
title: Exploring CO2-philic/ CO2-phobic amphiphiles, cross-linkers and HC-polymers for 3D-structured rod-like aggregates in supercritical CO2

description: Over the last two decades, many polymers have been tested to increase CO2 viscosity for applications in enhanced oil recovery using CO2 (CO2-EOR). Unfortunately, conventional HC-polymers were inactive for viscosity enhancements due to their poor solubility in supercritical CO2 (scCO2). Recent SANS studies (RB1720361, RB1820137) found that tailor-made CO2-philic/ CO2-phobic amphiphiles formed rod-like aggregates (RAs) encapsulating HC-polymers in scCO2. The length of RAs was strongly dependent on both the architectures and concentrations of the amphiphiles and HC-polymers. To develop inexpensive, environmental-friendly and effective HC-polymer-based CO2-thickners for CO2-EOR, this experiment will explore optimum structures, concentrations, and compositions of amphiphiles, cross-linkers and HC-polymers to generate 3D-structured networks of RAs with HC-polymer backbones in scCO2.
DOI: 10.5286/isis.e.rb1920310
title: Paramagnetic excitations in the topological Weyl semimetal Co3Sn2S2

description: In a magnetic Weyl semimetal (WSM) with broken time-reversal symmetry, large intrinsic anomalous Hall effect is expected if the Weyl nodes are close to Fermi energy, which mostly depends on the orbital magnetism from itinerant electrons. Recently, a layered Kagomé-lattice half-metal Co3Sn2S2 with Weyl points near Fermi energy and a ferromagnetic transition around 175 K, is discovered to be an ideal ferromagnetic WSM. Our previous results on triple-axis spectrometer and time-of-flight spectrometer Merlin (RB1820002) helped us clear the three-dimensional spin exchange coupling and its spectrum of spin waves. Here we propose to do more temperature dependent measurements on the same sample measured on Merlin. The aim is to further understand the temperature evolution of the spin excitations in Co3Sn2S2 and its connection with the non-monotonic temperature dependence of anomalous Hall angle.
DOI: 10.5286/isis.e.rb1920376
title: Characterization of the depth profiling of the surface gilding of three detached components of the south Gate of Firenze Baptistery

description: The South Gate of Florence Baptistery is a 3 meters high gilded bronze artifact designed by Andrea Pisano and cast by Lorenzo DAvanzo and co-workers between 1329 and 1336. It is one of the oldest Middle Ages bronze gates in existence in Europe. In order to gain the highest amount of information about the gate manufacturing method, we plan to use neutron and muon techniques on three detached components. Our goal consists in the investigation of the casting and gilding manufacturing procedures by identifying: a) number and position of the casting channels; b) composition and homogeneity of the brass alloy in the different areas; c) general quality of the casting through the identification of the presence and size of bubbles, flaws and defects; d) composition and thickness of the mercury amalgam gilding. Negative muons depth profiling will be used to ansewer question "d".
DOI: 10.5286/isis.e.rb1920376-1
title: Characterization of the depth profiling of the surface gilding of three detached components of the south Gate of Firenze Baptistery

description: The South Gate of Florence Baptistery is a 3 meters high gilded bronze artifact designed by Andrea Pisano and cast by Lorenzo DAvanzo and co-workers between 1329 and 1336. It is one of the oldest Middle Ages bronze gates in existence in Europe. In order to gain the highest amount of information about the gate manufacturing method, we plan to use neutron and muon techniques on three detached components. Our goal consists in the investigation of the casting and gilding manufacturing procedures by identifying: a) number and position of the casting channels; b) composition and homogeneity of the brass alloy in the different areas; c) general quality of the casting through the identification of the presence and size of bubbles, flaws and defects; d) composition and thickness of the mercury amalgam gilding. Negative muons depth profiling will be used to ansewer question "d".
DOI: 10.5286/isis.e.rb1920560
title: Local Li-diffusion behaviour in high nickel content electrodes for future EV battery applications

description: The development of high energy density electrode materials is increasingly important for EV applications. Chief amongst these are the layered oxide materials LiNixMnyCozO2, where increased nickel content can increase the overall energy density (e.g. NMC-622, NMC-811). Although many benefits arise from high nickel content cathode materials, several new challenges arise including increased degradation over long term cycling. One strategy to alleviate this is to dope with, for example, small amounts of aluminium. The nature of this and the mechanism by which doping improves capacity retention is not well understood. We propose to investigate a series of high nickel content NMCs (pristine and doped) to investigate this effect and determine the benefits of the synthetic methodology applied.
DOI: 10.5286/isis.e.rb1920560-1
title: Local Li-diffusion behaviour in high nickel content electrodes for future EV battery applications

description: The development of high energy density electrode materials is increasingly important for EV applications. Chief amongst these are the layered oxide materials LiNixMnyCozO2, where increased nickel content can increase the overall energy density (e.g. NMC-622, NMC-811). Although many benefits arise from high nickel content cathode materials, several new challenges arise including increased degradation over long term cycling. One strategy to alleviate this is to dope with, for example, small amounts of aluminium. The nature of this and the mechanism by which doping improves capacity retention is not well understood. We propose to investigate a series of high nickel content NMCs (pristine and doped) to investigate this effect and determine the benefits of the synthetic methodology applied.
DOI: 10.5286/isis.e.rb1920595
title: Characterizing Mu in 6H-SiC with RF-MuSR

description: We propose a set of RF measurements on Silicon Carbide (polytype 6H) to identify and characterize the muonium species present below room temperature. One of the main goals of characterizing muonium with this experiment is to provide data that is essential to the analysis and interpretation of our recent experiment (RB1910567) where we used the laser system on HIFI to directly ionize Mu centers in an effort to directly measure the muonium impurity levels. In semiconductors, isolated hydrogen is electrically active and unavoidable in both material production and use. The high reactivity of H makes it a very interesting impurity but also very difficult to study. Muons have been very successful in functioning as an experimentally accessible analogue to isolated H impurities in materials. The proposed measurements will also add valuable information to the understanding of H impurities in SiC
DOI: 10.5286/isis.e.rb1920595-1
title: Characterizing Mu in 6H-SiC with RF-MuSR

description: We propose a set of RF measurements on Silicon Carbide (polytype 6H) to identify and characterize the muonium species present below room temperature. One of the main goals of characterizing muonium with this experiment is to provide data that is essential to the analysis and interpretation of our recent experiment (RB1910567) where we used the laser system on HIFI to directly ionize Mu centers in an effort to directly measure the muonium impurity levels. In semiconductors, isolated hydrogen is electrically active and unavoidable in both material production and use. The high reactivity of H makes it a very interesting impurity but also very difficult to study. Muons have been very successful in functioning as an experimentally accessible analogue to isolated H impurities in materials. The proposed measurements will also add valuable information to the understanding of H impurities in SiC
DOI: 10.5286/isis.e.rb1820525
title: Investigation of the relaxor-photoferroelectric Ba(Sn,Ti)O3 compounds using neutron pair distribution function

description: The local structural distortions in BaTiO3-based solid solutions, where the Ti4+ site is substituted by isovalent Sn4+ cation Ba(Sn,Ti)O3, are characterized by no oxygen tilts and predicted to promote different Ti(Sn)-O bonds leading to different polar orders through the phase diagram, from ferroelectrics to relaxors. The last ones are characterized by the presence of polar nanoclusters with different dynamic regimes depending on the Ti/Sn ratio. We carried out atomistic calculations indicating a distribution of Ti(Sn)-O bond distances for relaxor compositions, which is compatible with a local induced polarization on the Sn sites from the Ti ones. Neutron scattering pair distribution function on different compositions and at room and low temperature will allow us quantifying the local disorder on these compounds above and below the activation temperature of the polar nanoclusters.
DOI: 10.5286/isis.e.rb1820525-1
title: Investigation of the relaxor-photoferroelectric Ba(Sn,Ti)O3 compounds using neutron pair distribution function

description: The local structural distortions in BaTiO3-based solid solutions, where the Ti4+ site is substituted by isovalent Sn4+ cation Ba(Sn,Ti)O3, are characterized by no oxygen tilts and predicted to promote different Ti(Sn)-O bonds leading to different polar orders through the phase diagram, from ferroelectrics to relaxors. The last ones are characterized by the presence of polar nanoclusters with different dynamic regimes depending on the Ti/Sn ratio. We carried out atomistic calculations indicating a distribution of Ti(Sn)-O bond distances for relaxor compositions, which is compatible with a local induced polarization on the Sn sites from the Ti ones. Neutron scattering pair distribution function on different compositions and at room and low temperature will allow us quantifying the local disorder on these compounds above and below the activation temperature of the polar nanoclusters.
DOI: 10.5286/isis.e.rb1910341-2
title: Modulation in Molecular Materials under Pressure

description: Modulation has been understood and used to explain physical properties in solid-state materials for many years. Molecular modulated structures relatively scarce, but due to technological advances can no longer be ignored. Systematic variable temperature studies of the derivatives of Barluenga's Reagent has shed some light on why some of these salts exhibit modulation. Application of pressure allows the exploration of more of the phase diagram allowing access to new states and expanding our knowledge. A better understanding of the causes of modulation in simple molecular systems will aid our treatment of the pathological cases where solution currently eludes us.
DOI: 10.5286/isis.e.rb1920052
title: INS studies with MAPS of Nafion and model compounds

description: In the archetypal hydrogenoxygen proton exchange membrane fuel cell design, a proton-conducting polymer membrane (typically Nafion) contains the electrolyte solution that separates the anode and cathode sides. How water is distributed in the Nafion membrane is a continuing subject of investigation by a range of computational, spectroscopic and imaging techniques. In a previous proposal, TOSCA was used to characterise how the water is present in the polymer as a function of concentration. In this proposal, I wish to use MAPS to observe the O-H stretch and bend modes in the same Nafion samples and to measure a series of model compounds that contain a hydrated proton as H3O+, H5O2+ and hydrated clusters of these .