cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1920157-1
title: Structural evidence from SANS on self-assembly of antimicrobial lipopeptides and their interactions with small unilamellar vesicles

description: Previous studies have demonstrated that the de novo designed antimicrobial lipopeptides can self-assemble to beta-sheet nanofibers, but can transform to alpha-helical monomers once interacting with the anionic bacterial membranes. Following the above work, we propose to investigate the structural evidence of the self-assembly of lipopeptides by using small angel neutron scattering (SANS) to characterise the nanofibers before and after interactions with small unilamellar vesicles (SUVs). This work will provide valuable molecular insight of modes of action of the the lipopeptides to different model membranes.
DOI: 10.5286/isis.e.rb1920219
title: Identification of complex energy hierarchy in the coupled trimer spin system Ba4LuRu3O12

description: The weakly coupled spin cluster systems provide a fertile ground to study both zero-dimensional quantum and three-dimensional collective magnetism. Such spin cluster systems feature that the lower-energy magnetic excitations, including transverse and longitudinal magnon modes, emerge with gapped localized excitations concomitantly. The newly discovered trimer spin system Ba4LuRu3O12 constitutes Ru3O12 trimers made of three face-sharing RuO6 octahedra. The magnetic susceptibility of Ba4LuRu3O12 shows an antiferromagnetic order at TN = 8 K. However, the Curie-Wiess analysis of the magnetic susceptibility reveals that the local spin alignment of the Ru3O12 trimers varies with temperature. With the aid of inelastic neutron scattering, we will elucidate the energy-level scheme of the interacting spin trimer system and the underlying mechanism for the alteration of the spin configuration.
DOI: 10.5286/isis.e.rb1920219-1
title: Identification of complex energy hierarchy in the coupled trimer spin system Ba4LuRu3O12

description: The weakly coupled spin cluster systems provide a fertile ground to study both zero-dimensional quantum and three-dimensional collective magnetism. Such spin cluster systems feature that the lower-energy magnetic excitations, including transverse and longitudinal magnon modes, emerge with gapped localized excitations concomitantly. The newly discovered trimer spin system Ba4LuRu3O12 constitutes Ru3O12 trimers made of three face-sharing RuO6 octahedra. The magnetic susceptibility of Ba4LuRu3O12 shows an antiferromagnetic order at TN = 8 K. However, the Curie-Wiess analysis of the magnetic susceptibility reveals that the local spin alignment of the Ru3O12 trimers varies with temperature. With the aid of inelastic neutron scattering, we will elucidate the energy-level scheme of the interacting spin trimer system and the underlying mechanism for the alteration of the spin configuration.
DOI: 10.5286/isis.e.rb1920606
title: Longitudinal relaxation measurements in the ferromagnetic phase of the superconducting state of Eu-based pnictides

description: We aim to perform zero and longitudinal field muon spin relaxation measurements in order to investigate anomalous spin dynamics effects observed in EuFe2(As1-xPx)2 with x=0.20 when ferromagnetism and superconductivity coexist at low temperature. In this system the Curie temperature is lower than the superconducting critical temperature, hence it offers an optimal playground to explore the interplay between the coexisting orders. The interplay between superconductivity and magnetism remains one of the main enigmas in Physics. The ISIS muon facility is the most suitable to measure slow muon spin relaxations of the longitudinal component expected for this compound and will be complementary to other techniques with different time windows, such as microwave and ac magnetization measurements.
DOI: 10.5286/isis.e.rb1920606-2
title: Longitudinal relaxation measurements in the ferromagnetic phase of the superconducting state of Eu-based pnictides

description: We aim to perform zero and longitudinal field muon spin relaxation measurements in order to investigate anomalous spin dynamics effects observed in EuFe2(As1-xPx)2 with x=0.20 when ferromagnetism and superconductivity coexist at low temperature. In this system the Curie temperature is lower than the superconducting critical temperature, hence it offers an optimal playground to explore the interplay between the coexisting orders. The interplay between superconductivity and magnetism remains one of the main enigmas in Physics. The ISIS muon facility is the most suitable to measure slow muon spin relaxations of the longitudinal component expected for this compound and will be complementary to other techniques with different time windows, such as microwave and ac magnetization measurements.
DOI: 10.5286/isis.e.rb2000061-1
title: Demonstration of the elementary cell of a new compact neutron collimator

description: The INFN-Italy ANET collaboration developed a new design of neutron collimator that should be capable of greatly reducing the distances needed to collimate thermal neutron beams to the levels needed for most neutron inspection analysis and neutron science applications. A typical L/D value of 1000 could be achieved with a 2.5 meter long structure. If successfully tested, the innovating potential of this new collimator design for neutron science is very high. Facilities such as ISIS, ESS SNS, J-PARC would greatly benefit from it. The measurement will consist in the intensity analysis, with respect to the spatial coordinates, of the transmitted neutron signal through a typical elementary cell of this new collimator design.
DOI: 10.5286/isis.e.rb1920176
title: Membrane reconstitution of human dihydroorotate dehydrogenase using lipid-detergent micelles

description: Human dihydroorotate dehydrogenase (DHODH) is an integral membrane protein found in mitochondria involved in the biosynthesis of pyrimidines. DHODH oxidizes dihydroorotate with the simultaneous reduction of ubiquinone Q10 and is a well-validated target for anti-inflammatory and anti-proliferative drugs. We are investigating the mechanisms by which DHODH interacts with Q10 and clinical inhibitors in the inner mitochondrial membrane (IMM) and therefore develop methods to reconstitute it into physiologically lipid bilayers mimicking the IMM using phospholipid-detergent micelles. In this experiment, we propose will investigate for the first time the reconstitution of DHODH into supported bilayers from phospholipid-dodecyl-D-maltoside (DDM) micelles using contrasts variation to determine the composition and structure of the membrane during the deposition process.
DOI: 10.5286/isis.e.rb1920176-1
title: Membrane reconstitution of human dihydroorotate dehydrogenase using lipid-detergent micelles

description: Human dihydroorotate dehydrogenase (DHODH) is an integral membrane protein found in mitochondria involved in the biosynthesis of pyrimidines. DHODH oxidizes dihydroorotate with the simultaneous reduction of ubiquinone Q10 and is a well-validated target for anti-inflammatory and anti-proliferative drugs. We are investigating the mechanisms by which DHODH interacts with Q10 and clinical inhibitors in the inner mitochondrial membrane (IMM) and therefore develop methods to reconstitute it into physiologically lipid bilayers mimicking the IMM using phospholipid-detergent micelles. In this experiment, we propose will investigate for the first time the reconstitution of DHODH into supported bilayers from phospholipid-dodecyl-D-maltoside (DDM) micelles using contrasts variation to determine the composition and structure of the membrane during the deposition process.
DOI: 10.5286/isis.e.rb1920193
title: Neutron diffraction study on the lattice structure of rare-earth chalcogenides NaReSe2 (Re: Yb, Er and Lu)

description: The frustrated quantum magnets have attracted a lot of attention with the ability of hosting the exotic quantum spin states. It has been believed that the degenerate ground states of the system were induced by the competition between the interacting energies and geometrical properties of the crystal lattice at a specific given site. The quantum spin liquid(QSL) state is a frustrated quantum magnet with the unstable spins ordering state even in the zero-temperature limit. Therefore, it has been considered that QSLs have a prominent role in high-TC superconductors theory and in quantum computers. NaYbCh2 (Ch=O, S, Se) is a perfect QSL candidate with a hexagonal structure, R-3m. The Se-compound has larger distortion and small electronic band gap. In order to confirm the local information of Se-system, we propose to study the lattice structure of NaReSe2 (Re: Lu, Er, and Yb).
DOI: 10.5286/isis.e.rb1920193-1
title: Neutron diffraction study on the lattice structure of rare-earth chalcogenides NaReSe2 (Re: Yb, Er and Lu)

description: The frustrated quantum magnets have attracted a lot of attention with the ability of hosting the exotic quantum spin states. It has been believed that the degenerate ground states of the system were induced by the competition between the interacting energies and geometrical properties of the crystal lattice at a specific given site. The quantum spin liquid(QSL) state is a frustrated quantum magnet with the unstable spins ordering state even in the zero-temperature limit. Therefore, it has been considered that QSLs have a prominent role in high-TC superconductors theory and in quantum computers. NaYbCh2 (Ch=O, S, Se) is a perfect QSL candidate with a hexagonal structure, R-3m. The Se-compound has larger distortion and small electronic band gap. In order to confirm the local information of Se-system, we propose to study the lattice structure of NaReSe2 (Re: Lu, Er, and Yb).
DOI: 10.5286/isis.e.rb1920299
title: Investigation of crystal field excitations in correlated 4f3 systems NdT2Zn20 (T = Co, Rh, and Ir)

description: Recently, rare-earth-based RT2X20 (T: transition metal, X = Al, Zn and Cd) compounds have attracted much attention because of the weak crystalline electric field (CEF) effect and the enhanced hybridization effect. In the present proposal, we focus on the compounds NdT2Zn20 (T = Co, Rh, and Ir) with magnetic Gamma 6 doublets of 4f3 configuration. They exhibit antiferromagnetic orders at TN = 0.53, 0.94, and 0.65 K, respectively, for T = Co, Rh, and Ir. The electrical resistivity shows upward curvature above TN and the magnetic entropy is reduced to (0.5)Rln2 at TN, probably resulting from enhanced c-f hybridization and/or magnetic frustration in the Gamma 6 doublet of the Nd ion. To understand the observed reduction of the magnetic entropy in NdT2Zn20 through investigating the CEF level schemes, we plan to perform inelastic neutron scattering experiments with powdered samples.
DOI: 10.5286/isis.e.rb1920299-1
title: Investigation of crystal field excitations in correlated 4f3 systems NdT2Zn20 (T = Co, Rh, and Ir)

description: Recently, rare-earth-based RT2X20 (T: transition metal, X = Al, Zn and Cd) compounds have attracted much attention because of the weak crystalline electric field (CEF) effect and the enhanced hybridization effect. In the present proposal, we focus on the compounds NdT2Zn20 (T = Co, Rh, and Ir) with magnetic Gamma 6 doublets of 4f3 configuration. They exhibit antiferromagnetic orders at TN = 0.53, 0.94, and 0.65 K, respectively, for T = Co, Rh, and Ir. The electrical resistivity shows upward curvature above TN and the magnetic entropy is reduced to (0.5)Rln2 at TN, probably resulting from enhanced c-f hybridization and/or magnetic frustration in the Gamma 6 doublet of the Nd ion. To understand the observed reduction of the magnetic entropy in NdT2Zn20 through investigating the CEF level schemes, we plan to perform inelastic neutron scattering experiments with powdered samples.
DOI: 10.5286/isis.e.rb1920744
title: Non-invasive preservation assessment of archaeological bone using neutron imaging

description: The project seeks to answer questions regarding the appropriate storage and display conditions for archaeological bone objects in English Heritage collections. A recent national audit of the English Heritage collection has indicated that archaeological bone is among the most damaged materials. Exposure to low relative humidity (RH) has caused the loss of mechanical properties and in some cases structural failure. To build a more cohesive understanding of bone, a multi-scale multi-analytical approach is being used to determine the integrity of bone including the physicochemical state of collagen and DNA . However, much of this work is destructive and may not be applicable to all archaeological collections. Therefore there is a need within the project to seek non-invasive methods regarding preservation assessment. Neutron imaging has indicated that it could provide such a methodology.
DOI: 10.5286/isis.e.rb2000050
title: Exploring Reversibility within Compressible Liquids

description: Earlier this year, we discovered the world's most compressible liquid (CL) to date. With STFC scientists and facilities, it was analysed and was found to compress by 10% in volume under pressure (cf. 2-3% for water). The compression however, was irreversible - this was unexpected and not ideal for applications such as shock absorption. In September 2019, we were granted further access to the equipment used previously to pressurise the material. Interestingly, by adding small amounts (5%) of certain additives, the compression became reversible. This information will be an important aspect in a high impact publication on these groundbreaking materials. However, to include these latest results, the structure of the reversible system at the molecular level needs to be analysed. This beamtime application will enable such analysis and publication of a high impact paper.
DOI: 10.5286/isis.e.rb2000050-1
title: Exploring Reversibility within Compressible Liquids

description: Earlier this year, we discovered the world's most compressible liquid (CL) to date. With STFC scientists and facilities, it was analysed and was found to compress by 10% in volume under pressure (cf. 2-3% for water). The compression however, was irreversible - this was unexpected and not ideal for applications such as shock absorption. In September 2019, we were granted further access to the equipment used previously to pressurise the material. Interestingly, by adding small amounts (5%) of certain additives, the compression became reversible. This information will be an important aspect in a high impact publication on these groundbreaking materials. However, to include these latest results, the structure of the reversible system at the molecular level needs to be analysed. This beamtime application will enable such analysis and publication of a high impact paper.
DOI: 10.5286/isis.e.rb1920078
title: Comparison of the Compression Behaviour of BaSnO3 and Ba0.575Sr0.425SnO3

description: We propose to study the effect of pressure on the structure of the tetragonal Ba0.575Sr0.425SnO3, The behaviour will be compared to the compression of the cubic BaSnO3 (parent compound). At room temperature the perovskite system Ba1-xSrxSnO3 shows a series of phases in the sequence orthorhombic (Pbnm), orthorhombic (Ibmm), tetragonal (I4/mcm), and cubic (Pm-3m) [4]. These are a consequence of the sequential introduction of cooperative tilting of the corner sharing SnO6 octahedra resulting from the changes in the average A site size. Given that the effect of reducing the lanthanide ionic radii is equivalent to that of applyingpressure, it is theoretically possible to study the effect of A-site substitution on the structure using a single compound, hence such high pressure studies are useful for developing such models.
DOI: 10.5286/isis.e.rb1920078-1
title: Comparison of the Compression Behaviour of BaSnO3 and Ba0.575Sr0.425SnO3

description: We propose to study the effect of pressure on the structure of the tetragonal Ba0.575Sr0.425SnO3, The behaviour will be compared to the compression of the cubic BaSnO3 (parent compound). At room temperature the perovskite system Ba1-xSrxSnO3 shows a series of phases in the sequence orthorhombic (Pbnm), orthorhombic (Ibmm), tetragonal (I4/mcm), and cubic (Pm-3m) [4]. These are a consequence of the sequential introduction of cooperative tilting of the corner sharing SnO6 octahedra resulting from the changes in the average A site size. Given that the effect of reducing the lanthanide ionic radii is equivalent to that of applyingpressure, it is theoretically possible to study the effect of A-site substitution on the structure using a single compound, hence such high pressure studies are useful for developing such models.
DOI: 10.5286/isis.e.rb1920078-2
title: Comparison of the Compression Behaviour of BaSnO3 and Ba0.575Sr0.425SnO3

description: We propose to study the effect of pressure on the structure of the tetragonal Ba0.575Sr0.425SnO3, The behaviour will be compared to the compression of the cubic BaSnO3 (parent compound). At room temperature the perovskite system Ba1-xSrxSnO3 shows a series of phases in the sequence orthorhombic (Pbnm), orthorhombic (Ibmm), tetragonal (I4/mcm), and cubic (Pm-3m) [4]. These are a consequence of the sequential introduction of cooperative tilting of the corner sharing SnO6 octahedra resulting from the changes in the average A site size. Given that the effect of reducing the lanthanide ionic radii is equivalent to that of applyingpressure, it is theoretically possible to study the effect of A-site substitution on the structure using a single compound, hence such high pressure studies are useful for developing such models.
DOI: 10.5286/isis.e.rb1920396
title: muSR investigation of spin-orbit coupling driven magnetism of Ba3Zn1-xNixIr2O9 (x=0.15, 1)

description: Strong spin-orbit coupling (SOC) in 5d transition metal oxides very often leads to unexpectedelectronic and magnetic ground state. While a nonmagnetic J=0 ground state can be anticipatedfrom j-j coupling scheme of 5d4 system, the competition among SOC, crystal field splitting,hopping and electron correlation makes it very rare to realize such J=0 state. Singlet to tripletexcitation can also result small moment and antiferromagnetic interactions among these spins in ageometrically frustrated lattice can give rise to spin-orbit liquid phase. We propose to study musrinvestigation of magnetic ground state of several hexagonal iridates with d4 configuration infrustrated lattice geometry, where we have tuned the exitonic magnetic moment of Ir5+ ionthrough judicial chemical doping, which does not change oxidation state of Ir.
DOI: 10.5286/isis.e.rb1920396-1
title: muSR investigation of spin-orbit coupling driven magnetism of Ba3Zn1-xNixIr2O9 (x=0.15, 1)

description: Strong spin-orbit coupling (SOC) in 5d transition metal oxides very often leads to unexpectedelectronic and magnetic ground state. While a nonmagnetic J=0 ground state can be anticipatedfrom j-j coupling scheme of 5d4 system, the competition among SOC, crystal field splitting,hopping and electron correlation makes it very rare to realize such J=0 state. Singlet to tripletexcitation can also result small moment and antiferromagnetic interactions among these spins in ageometrically frustrated lattice can give rise to spin-orbit liquid phase. We propose to study musrinvestigation of magnetic ground state of several hexagonal iridates with d4 configuration infrustrated lattice geometry, where we have tuned the exitonic magnetic moment of Ir5+ ionthrough judicial chemical doping, which does not change oxidation state of Ir.
DOI: 10.5286/isis.e.rb1920645
title: Magnetic order in Tm2Si2O7

description: We propose to probe the magnetic ground state of Tm2Si2O7 with neutron diffraction. The compound belongs to a family of rare-earth disilicates, whose magnetic properties remain largely unknown. Tm2Si2O7 has a monoclinic structure (C type), identical to the one found in Yb2Si2O7, where highly unusual low-T magnetic phase diagram has recently been reported. Our heat capacity measurements suggest that Tm2Si2O7 remains magnetically disordered down to at least 0.4 K, we therefore need a dilution refrigerator to reach sub 1 K temperatures.
DOI: 10.5286/isis.e.rb1920645-1
title: Magnetic order in Tm2Si2O7

description: We propose to probe the magnetic ground state of Tm2Si2O7 with neutron diffraction. The compound belongs to a family of rare-earth disilicates, whose magnetic properties remain largely unknown. Tm2Si2O7 has a monoclinic structure (C type), identical to the one found in Yb2Si2O7, where highly unusual low-T magnetic phase diagram has recently been reported. Our heat capacity measurements suggest that Tm2Si2O7 remains magnetically disordered down to at least 0.4 K, we therefore need a dilution refrigerator to reach sub 1 K temperatures.
DOI: 10.5286/isis.e.rb1920645-2
title: Magnetic order in Tm2Si2O7

description: We propose to probe the magnetic ground state of Tm2Si2O7 with neutron diffraction. The compound belongs to a family of rare-earth disilicates, whose magnetic properties remain largely unknown. Tm2Si2O7 has a monoclinic structure (C type), identical to the one found in Yb2Si2O7, where highly unusual low-T magnetic phase diagram has recently been reported. Our heat capacity measurements suggest that Tm2Si2O7 remains magnetically disordered down to at least 0.4 K, we therefore need a dilution refrigerator to reach sub 1 K temperatures.
DOI: 10.5286/isis.e.rb1920744-1
title: Non-invasive preservation assessment of archaeological bone using neutron imaging

description: The project seeks to answer questions regarding the appropriate storage and display conditions for archaeological bone objects in English Heritage collections. A recent national audit of the English Heritage collection has indicated that archaeological bone is among the most damaged materials. Exposure to low relative humidity (RH) has caused the loss of mechanical properties and in some cases structural failure. To build a more cohesive understanding of bone, a multi-scale multi-analytical approach is being used to determine the integrity of bone including the physicochemical state of collagen and DNA . However, much of this work is destructive and may not be applicable to all archaeological collections. Therefore there is a need within the project to seek non-invasive methods regarding preservation assessment. Neutron imaging has indicated that it could provide such a methodology.
DOI: 10.5286/isis.e.rb1920009
title: Structures of phenol-ammonia and phenol-water compounds

description: Phenol-water and phenol-ammonia clusters are useful model systems for understanding the types of proton-transfer interactions that occur during photosynthesis in plants and bacteria. However, almost nothing is known about these complexes in the solid state. Since these appear to be excellent candidates to undergo solid-state proton transfer under slight degrees of compression, structure determinations at low temperature and later under hydrostatic pressure are required. The aim of this work is to carry out low-temperature structural characterisation of the known phases, phenol hemihydrate, phenol mono-ammoniate and phenol di-ammoniate. Furthermore, I propose to evaluate the possible existence of an ammonia-rich phase with a phenol to ammonia ratio of about 9:1.
DOI: 10.5286/isis.e.rb1920009-1
title: Structures of phenol-ammonia and phenol-water compounds

description: Phenol-water and phenol-ammonia clusters are useful model systems for understanding the types of proton-transfer interactions that occur during photosynthesis in plants and bacteria. However, almost nothing is known about these complexes in the solid state. Since these appear to be excellent candidates to undergo solid-state proton transfer under slight degrees of compression, structure determinations at low temperature and later under hydrostatic pressure are required. The aim of this work is to carry out low-temperature structural characterisation of the known phases, phenol hemihydrate, phenol mono-ammoniate and phenol di-ammoniate. Furthermore, I propose to evaluate the possible existence of an ammonia-rich phase with a phenol to ammonia ratio of about 9:1.