cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb2010672
title: Crystal Field Levels in Cerium Hafnate: a New Quantum Spin Liquid

description: A theoretically predicted Octupolar QSI was found in the Ce2Sn2O7 pyrochlore oxide. The presence of a dipole-octupole ground state doublet explains remarkably well macroscopic measurements and crystal-field analysis. Furthermore, the octupolar nature of the correlations has been observed, taking the shape of a broad hump located at high momentum transfer in neutron diffraction patterns. Unfortunately, the chemistry of Ce2Sn2O7 makes it challenging to grow single crystals to further elucidate the nature of its ground state. However, it is possible for its parent compound, Ce2Hf2O7. Its chemical and physical similarities with Ce2Sn2O7 motivate its investigation as it could withstand undoubtable fingerprints of this Octupolar QSI. We propose to probe Ce2Hf2O7 crystal field levels of as they play a crucial role in determining the system’s ground state wavefunction and to its understanding.
DOI: 10.5286/isis.e.rb2010672-1
title: Crystal Field Levels in Cerium Hafnate: a New Quantum Spin Liquid

description: A theoretically predicted Octupolar QSI was found in the Ce2Sn2O7 pyrochlore oxide. The presence of a dipole-octupole ground state doublet explains remarkably well macroscopic measurements and crystal-field analysis. Furthermore, the octupolar nature of the correlations has been observed, taking the shape of a broad hump located at high momentum transfer in neutron diffraction patterns. Unfortunately, the chemistry of Ce2Sn2O7 makes it challenging to grow single crystals to further elucidate the nature of its ground state. However, it is possible for its parent compound, Ce2Hf2O7. Its chemical and physical similarities with Ce2Sn2O7 motivate its investigation as it could withstand undoubtable fingerprints of this Octupolar QSI. We propose to probe Ce2Hf2O7 crystal field levels of as they play a crucial role in determining the system’s ground state wavefunction and to its understanding.
DOI: 10.5286/isis.e.rb2000145
title: Properties of plant specific membranes and their interactions with toxins from important agricultural pathogens - continuation

description: Many devastating plant diseases, including those of essential food crop plants, are caused by microbes such as bacteria, fungi and “fungi-like” organisms called oomycetes. We recently discovered that all three groups use similar protein toxins (NLP) to damage plant cells. They bind a class of lipid molecules found only in plant cell membranes. These lipids, called glycosylinositol phosphoceramides (GIPC), are found exclusively in plants and little is known about the properties of lipid membranes containing them. Our initial 2 days of neutron experiments revealed the structure of GIPC containing membranes and how the NLP toxins bind the membrane. However we don't know how this damages the cell and need to understand how far the toxin penetrates into the plant cell membrane. We wish to have 2 days more beam time to carry out the essential extra experiments prior to publishing our paper..
DOI: 10.5286/isis.e.rb2000145-1
title: Properties of plant specific membranes and their interactions with toxins from important agricultural pathogens - continuation

description: Many devastating plant diseases, including those of essential food crop plants, are caused by microbes such as bacteria, fungi and “fungi-like” organisms called oomycetes. We recently discovered that all three groups use similar protein toxins (NLP) to damage plant cells. They bind a class of lipid molecules found only in plant cell membranes. These lipids, called glycosylinositol phosphoceramides (GIPC), are found exclusively in plants and little is known about the properties of lipid membranes containing them. Our initial 2 days of neutron experiments revealed the structure of GIPC containing membranes and how the NLP toxins bind the membrane. However we don't know how this damages the cell and need to understand how far the toxin penetrates into the plant cell membrane. We wish to have 2 days more beam time to carry out the essential extra experiments prior to publishing our paper..
DOI: 10.5286/isis.e.rb2000166
title: ISIS@MACH - Inelastic Neutron Scattering investigation of Ancient Roman’s Aebutia Quarta human skeletal remains

description: The “Hypogeum of the Garlands” is an extraordinary ancient Roman sepulchral site dated back of I-II century AD and discovered in 2000 at Grottaferrata (Rome). The site includes two sarcophagi, identified as Aebutia Quarta and Carvilius Gemellus, which have original sealing and additional human skeletal combusted remains. The Aebutia and Carvilium remains are well preserved, showing still intact decorations with vegetal garlands. Aebutia Quarta remains show traces of possible combustion of the bones, associated with a probable thermal deformation. We propose to perform an inelastic neutron scattering investigation in TOSCA to measure the whole neutron vibrational spectra of these ancient bones with high sensitivity, with a view to better understand the changes undergone by the samples.
DOI: 10.5286/isis.e.rb2000166-1
title: ISIS@MACH - Inelastic Neutron Scattering investigation of Ancient Roman’s Aebutia Quarta human skeletal remains

description: The “Hypogeum of the Garlands” is an extraordinary ancient Roman sepulchral site dated back of I-II century AD and discovered in 2000 at Grottaferrata (Rome). The site includes two sarcophagi, identified as Aebutia Quarta and Carvilius Gemellus, which have original sealing and additional human skeletal combusted remains. The Aebutia and Carvilium remains are well preserved, showing still intact decorations with vegetal garlands. Aebutia Quarta remains show traces of possible combustion of the bones, associated with a probable thermal deformation. We propose to perform an inelastic neutron scattering investigation in TOSCA to measure the whole neutron vibrational spectra of these ancient bones with high sensitivity, with a view to better understand the changes undergone by the samples.
DOI: 10.5286/isis.e.rb2000154
title: Exploring the magnetic transitions in an Inverse Vanadium Spinal oxide

description: The spinel vanadates, AV2O4, are captivating, complex magnets, in particular in studying the role of orbital degrees of freedom in frustrated antiferromagnets. We propose to investigate the much less studied inverse spinel Co2VO4, where the B-site has mixed occupancy by two distinct magnetic ions, V4+ and low-spin Co2+. Our preliminary results show three distinct magnetic-phase transitions, among which a spontaneous irreversible magnetization reversal transition at 75 K. Contrary to the other two magnetic transitions at 165 and 145 K, this magnetization reversal is not evident in zero-field neutron powder diffraction. To fully understand the nature of the magnetic transitions at 165, 145, and especially at 75 K, we propose to carry out systematic zero-field µSR experiments as a function of temperature and longitudinal field µSR experiments, above and below all transition temperatures.
DOI: 10.5286/isis.e.rb2000154-1
title: Exploring the magnetic transitions in an Inverse Vanadium Spinal oxide

description: The spinel vanadates, AV2O4, are captivating, complex magnets, in particular in studying the role of orbital degrees of freedom in frustrated antiferromagnets. We propose to investigate the much less studied inverse spinel Co2VO4, where the B-site has mixed occupancy by two distinct magnetic ions, V4+ and low-spin Co2+. Our preliminary results show three distinct magnetic-phase transitions, among which a spontaneous irreversible magnetization reversal transition at 75 K. Contrary to the other two magnetic transitions at 165 and 145 K, this magnetization reversal is not evident in zero-field neutron powder diffraction. To fully understand the nature of the magnetic transitions at 165, 145, and especially at 75 K, we propose to carry out systematic zero-field µSR experiments as a function of temperature and longitudinal field µSR experiments, above and below all transition temperatures.
DOI: 10.5286/isis.e.rb2010519-2
title: Investigation of isonicotinamide confined within mesoporous silicon at high pressure

description: Our aim is to investigate the impact of confinement on the high pressure phase transition of isonicotinamide using PEARL. Confinement in a porous silicon guest host leads to nanocrystals with greater surface and greater free energy which should lead to an easier phase transition. Neutron diffraction will allow for greater detection of the isonicotinamide molecules confined within the pores of the host guest which heavily scatters X-rays.
DOI: 10.5286/isis.e.rb2010773
title: Fluorescent Labelling of Viruses for Rapid Optical Identification of Viral Pathogens

description: Infectious diseases caused by viruses such as influenza, HIV, Ebola, measles, Zika and hepatitis represent a huge global public health concern, causing many thousands of deaths annually. During the last two years we have worked on developing methods for the rapid fluorescent labelling of viruses, with the aim of developing an optical biosensor for virus detection based on fluorescent ribonucleic acid binding agents. We aim to use neutron reflectometry to characterise the exact mechanism of fluorescence labelling on the membrane surface of enveloped virus particles. Our experiments to date suggest that efficient fluorescence labelling of enveloped viruses requires the presence of a divalent cations fluorescently-labelled nucleic acid and anionic lipid bilayers on the virus particle. We will model this interaction using supported lipid bilayers to gain precision molecular information.
DOI: 10.5286/isis.e.rb2010773-1
title: Fluorescent Labelling of Viruses for Rapid Optical Identification of Viral Pathogens

description: Infectious diseases caused by viruses such as influenza, HIV, Ebola, measles, Zika and hepatitis represent a huge global public health concern, causing many thousands of deaths annually. During the last two years we have worked on developing methods for the rapid fluorescent labelling of viruses, with the aim of developing an optical biosensor for virus detection based on fluorescent ribonucleic acid binding agents. We aim to use neutron reflectometry to characterise the exact mechanism of fluorescence labelling on the membrane surface of enveloped virus particles. Our experiments to date suggest that efficient fluorescence labelling of enveloped viruses requires the presence of a divalent cations fluorescently-labelled nucleic acid and anionic lipid bilayers on the virus particle. We will model this interaction using supported lipid bilayers to gain precision molecular information.
DOI: 10.5286/isis.e.rb1920217
title: Spin excitations in the multi-Q magnetic order of CeAl2

description: Since several decades, heavy fermion (HF) materials have been studied as model systems to understand the emergent properties of strongly correlated metals. Although, the underlying magnetic interactions are widely expected to be crucial for understanding these properties, they only have been studied in few model HF materials. Recently, several analytical and numerical theoretical studies have suggested that frustrated RKKY interactions and Ising magnetic anisotropy may also lead to the formation of a skyrmions lattice state. CeAl2 is a HF compound, which orders in an antiferromagnetic multi-Q state, making it a candidate for a HF material with skyrmion ordering. We propose to take advantage of high-resolution time-of-flight neutron spectroscopy to determine the full magnon dispersion relation and underlying magnetic interactions in the ordered state of CeAl2.
DOI: 10.5286/isis.e.rb1920217-1
title: Spin excitations in the multi-Q magnetic order of CeAl2

description: Since several decades, heavy fermion (HF) materials have been studied as model systems to understand the emergent properties of strongly correlated metals. Although, the underlying magnetic interactions are widely expected to be crucial for understanding these properties, they only have been studied in few model HF materials. Recently, several analytical and numerical theoretical studies have suggested that frustrated RKKY interactions and Ising magnetic anisotropy may also lead to the formation of a skyrmions lattice state. CeAl2 is a HF compound, which orders in an antiferromagnetic multi-Q state, making it a candidate for a HF material with skyrmion ordering. We propose to take advantage of high-resolution time-of-flight neutron spectroscopy to determine the full magnon dispersion relation and underlying magnetic interactions in the ordered state of CeAl2.
DOI: 10.5286/isis.e.rb2010763
title: Seeking experimental proof of anionic redox in high capacity cathodes 1.

description: The high capacities (&gt; 250 mAh g–1) of Li-cathode materials have been attributed to reversible anionic redox stabilized by the formation of ‘peroxo-like’ O-O dimers in layered (Li/Na)2RuO3 and 3D β-Li2IrO3 structures. The formation of peroxo-like dimers is believed to stabilize O2-/O1.5- redox by the sharing of one electron hole between each oxygen in the pair. Peroxo-like distances have been proposed by Bragg diffraction, TEM or EXAFS. Unlike PDF, these techniques are not a direct probe of actual distribution of 𝑑 interatomic distances, and large uncertainties surround the estimated distances or existence of peroxo-like dimers. We propose to study the origin of anionic redox in Li0.5RuO3 and Na0.5RuO3 c by a new and comprehensive approach combining PDF and advanced spectroscopies that we have been successfully implemented in the characterization Mn-based high capacity cathodes.
DOI: 10.5286/isis.e.rb2010763-1
title: Seeking experimental proof of anionic redox in high capacity cathodes 1.

description: The high capacities (&gt; 250 mAh g–1) of Li-cathode materials have been attributed to reversible anionic redox stabilized by the formation of ‘peroxo-like’ O-O dimers in layered (Li/Na)2RuO3 and 3D β-Li2IrO3 structures. The formation of peroxo-like dimers is believed to stabilize O2-/O1.5- redox by the sharing of one electron hole between each oxygen in the pair. Peroxo-like distances have been proposed by Bragg diffraction, TEM or EXAFS. Unlike PDF, these techniques are not a direct probe of actual distribution of 𝑑 interatomic distances, and large uncertainties surround the estimated distances or existence of peroxo-like dimers. We propose to study the origin of anionic redox in Li0.5RuO3 and Na0.5RuO3 c by a new and comprehensive approach combining PDF and advanced spectroscopies that we have been successfully implemented in the characterization Mn-based high capacity cathodes.
DOI: 10.5286/isis.e.rb2000155
title: Residual stress and SCC studies of additively manufactured stainless steel by neutron imaging

description: The aim of the present proposal is to use the neutron Bragg-edge imaging technique to measure the deep internal residual strain in large additively manufactured stainless steel (SS) parts which cannot be measurable with other means. The proposed measurements are part of an in-depth study, involving several complementary techniques that cover a wide length scale. The outcome of the proposed work will support the explanation of the stress corrosion cracking (SCC) behavior of studied material in the recently funded SAMCO project where the overall goal of the research is the characterization of the interplay between SCC, additive manufacturing (AM) process parameters and, post-processing.
DOI: 10.5286/isis.e.rb2000155-1
title: Residual stress and SCC studies of additively manufactured stainless steel by neutron imaging

description: The aim of the present proposal is to use the neutron Bragg-edge imaging technique to measure the deep internal residual strain in large additively manufactured stainless steel (SS) parts which cannot be measurable with other means. The proposed measurements are part of an in-depth study, involving several complementary techniques that cover a wide length scale. The outcome of the proposed work will support the explanation of the stress corrosion cracking (SCC) behavior of studied material in the recently funded SAMCO project where the overall goal of the research is the characterization of the interplay between SCC, additive manufacturing (AM) process parameters and, post-processing.
DOI: 10.5286/isis.e.rb2010390
title: Chemical and physical pressure-tuned magneto-structural coupling in MnCoGe alloys

description: MnCoGe alloys show a variety of intriguing phenomena like magneto-caloric effect, baro-caloric effect and negative thermal expansion. Our recent results show that chemical and physical pressures play similar roles in coupling/decoupling the magnetic and structural transitions in the MnCoGe alloys. Both of them vary the interatomic distances, which strongly influences the magnetic interactions and chemical bonds. Nevertheless, unlike its chemical couterpart, the physical pressure does not suffer from parasitic effets originating in the substitution itself, since it retains the composition, purity and the number of valence electrons in the sample. Consequently, a comprehensive study on the evolution of the magnetic and crystallographic structures under chemical and physical pressures can provide essential insight into the origin of the magneto-structural transition in the MnCoGe alloys.
DOI: 10.5286/isis.e.rb2010390-1
title: Chemical and physical pressure-tuned magneto-structural coupling in MnCoGe alloys

description: MnCoGe alloys show a variety of intriguing phenomena like magneto-caloric effect, baro-caloric effect and negative thermal expansion. Our recent results show that chemical and physical pressures play similar roles in coupling/decoupling the magnetic and structural transitions in the MnCoGe alloys. Both of them vary the interatomic distances, which strongly influences the magnetic interactions and chemical bonds. Nevertheless, unlike its chemical couterpart, the physical pressure does not suffer from parasitic effets originating in the substitution itself, since it retains the composition, purity and the number of valence electrons in the sample. Consequently, a comprehensive study on the evolution of the magnetic and crystallographic structures under chemical and physical pressures can provide essential insight into the origin of the magneto-structural transition in the MnCoGe alloys.
DOI: 10.5286/isis.e.rb2000019
title: Uncover the magneto-structural coupling in the MnCoGe-based magnetocaloric alloys

description: Our recent results show that including 1 at.% of boron atoms in the MnCoGe alloy can make the otherwise separated ferromagnetic and orthorhombic-hexagonal structural transitions coincide, i.e. the realization of a magneto-structural transition. This leads to a giant magnetocaloric effect. However, the coupling mechanism of the magnetic and structural transitions is still not clear. Magnetic measurements suggest partial quenching of sublattice magnetic moments during the structural transition. We have solved the magnetic structure of the orthorhombic phase using neutron diffraction. Here we propose to perform neutron diffraction on the hexagonal MnCoGe phase. This work will allow us to elucidate the roles of the Mn and Co moments in the magneto-structural transition as well as the interplay between the magnetic and structural transition in the MnCoGe-based magnetocaloric materials.
DOI: 10.5286/isis.e.rb2000019-1
title: Uncover the magneto-structural coupling in the MnCoGe-based magnetocaloric alloys

description: Our recent results show that including 1 at.% of boron atoms in the MnCoGe alloy can make the otherwise separated ferromagnetic and orthorhombic-hexagonal structural transitions coincide, i.e. the realization of a magneto-structural transition. This leads to a giant magnetocaloric effect. However, the coupling mechanism of the magnetic and structural transitions is still not clear. Magnetic measurements suggest partial quenching of sublattice magnetic moments during the structural transition. We have solved the magnetic structure of the orthorhombic phase using neutron diffraction. Here we propose to perform neutron diffraction on the hexagonal MnCoGe phase. This work will allow us to elucidate the roles of the Mn and Co moments in the magneto-structural transition as well as the interplay between the magnetic and structural transition in the MnCoGe-based magnetocaloric materials.
DOI: 10.5286/isis.e.rb2000019-2
title: Uncover the magneto-structural coupling in the MnCoGe-based magnetocaloric alloys

description: Our recent results show that including 1 at.% of boron atoms in the MnCoGe alloy can make the otherwise separated ferromagnetic and orthorhombic-hexagonal structural transitions coincide, i.e. the realization of a magneto-structural transition. This leads to a giant magnetocaloric effect. However, the coupling mechanism of the magnetic and structural transitions is still not clear. Magnetic measurements suggest partial quenching of sublattice magnetic moments during the structural transition. We have solved the magnetic structure of the orthorhombic phase using neutron diffraction. Here we propose to perform neutron diffraction on the hexagonal MnCoGe phase. This work will allow us to elucidate the roles of the Mn and Co moments in the magneto-structural transition as well as the interplay between the magnetic and structural transition in the MnCoGe-based magnetocaloric materials.
DOI: 10.5286/isis.e.rb2010389
title: Understanding the Role of Solvent Additives in Organic Photovoltaic Blends

description: At Sheffield, organic solar cells (OSCs) have been made using a new class of materials called non-fullerene acceptors (NFAs) producing high efficiency devices (9-11%) in polymer blends. For OSCs containing ITIC, a NFA, the inclusion of solvent additives (e.g. 1,8-diioodocatane (DIO)) in the blend solution increases efficiency at a detriment to stability. This is not observed in OSCs containing PCBM, a more traditional material. SANS measurements at ISIS will allow us to probe the morphological stability of blend films by characterising the phase separation length scale between blend components. We also plan to do NR at D17, ILL on similar samples to study the vertical composition profiles of the blend films. SANS and NR will link the bulk morphology of the blends to device performance, helping us achieve high efficiency OSCs with real-world stability.
DOI: 10.5286/isis.e.rb2010389-1
title: Understanding the Role of Solvent Additives in Organic Photovoltaic Blends

description: At Sheffield, organic solar cells (OSCs) have been made using a new class of materials called non-fullerene acceptors (NFAs) producing high efficiency devices (9-11%) in polymer blends. For OSCs containing ITIC, a NFA, the inclusion of solvent additives (e.g. 1,8-diioodocatane (DIO)) in the blend solution increases efficiency at a detriment to stability. This is not observed in OSCs containing PCBM, a more traditional material. SANS measurements at ISIS will allow us to probe the morphological stability of blend films by characterising the phase separation length scale between blend components. We also plan to do NR at D17, ILL on similar samples to study the vertical composition profiles of the blend films. SANS and NR will link the bulk morphology of the blends to device performance, helping us achieve high efficiency OSCs with real-world stability.