cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1720411
title: Development of High-Resolution Neutron Transmission Strain Mapping: Comparison and Validation using Neutron Diffraction

description: High-resolution neutron transmission strain mapping is under development at ISIS to be implemented at IMAT, ENGIN-X and the newly proposed ε-MAP instrument. Transmission data obtained on IMAT using a microchannel plate (MCP) detector have been analysed using different Bragg edge analysis methods, and started generating strain information.  Key instrumental issues especially for low-attenuating samples, can be addressed with diffraction and transmission measurements on ENGIN-X on aluminium samples with well-defined strain profiles, owing to ENGIN-Xs well-characterised strain analysis capabilities. The objective of this technical study is to validate strain results derived from neutron transmission analysis, determine the accuracy and robustness of different Bragg edge analysis software tools, and evaluate and minimise the required counting times.
DOI: 10.5286/isis.e.rb1800051
title: Optimization of anticoincidence setup for Compton Suppression in Prompt Gamma Activation Analysis

description: Beam time is required to test the proper functioning of anti-coincident set-up specifically designed to actualize Compton suppression in Prompt Gamma Activation Analysis spectra at ISIS Neutron Source. The elimination of  background component, present in all these spectra so far acquired using only one High Purity germanium detector (HPGe), limits the correct identification of peaks but above all limits the signal-to-background ratio directly related to signal quality.
DOI: 10.5286/isis.e.rb1810098
title: Physical aspects of improving the fatigue strength of high strength steel welded structures

description: This project will investigate the physical aspects of improving the fatigue performance (strength) of high-strength steel welded joints, such as for the use in construction equipment, transportation vehicles and lifting devices, in order to obtain significant weight reduction and improved service life. The samples will be manufactured from plate thicknesses of 6 mm with yield strengths of 355 and 690 MPa. We will examine the well-known fatigue strength improvement technique called high frequency mechanical impact (HFMI) treatment method. Experimental measurements at ISIS will allow mapping the physical characterization and determining residual stress of the welds through the plate thickness. We will develop analytical procedures to assess the benefits and limitations of the treatment method.
DOI: 10.5286/isis.e.rb1810728
title: Local structure study of non-graphitisable carbon anode for sodium batteries

description: Na-ion-batteries (NIB) are one of the most promising candidates for future low-cost energy-storage technologies. Due to the large size of Na ions, conventional anode materials for Lithium-ion-batteries cannot be used in NIBs. However, nongraphitisable carbons, also called hard carbon, have been found to have good reversible capacities and cycle life when used as the anode material. The storage mechanism of Na ion in the hard carbon has been studied by many workers, but remains controversial with different explanations. We propose to perform neutron total scattering on a series of Na-ion-charged nongraphitisable carbons anodes to probe the behaviour of Na ions in these materials to better understand storage mechanism in the nongraphitizable carbons. The findings will provide theoretical insights for design of high performance hard carbons for NIBs.
DOI: 10.5286/isis.e.rb1820111
title: Magnetism and electronic structure of 3d  5d double perovskites

description: Emerging technologies require increasingly unusual functional materials and so understanding the origins of complex magnetic and electronic behaviour, and how these can be tuned, is increasingly important. The perovskite structure is an ongoing focus of materials research because it can accommodate a huge range of elements to give tailored physical properties. Our proposal focuses on double perovskites, containing both light and heavy magnetic ions. These materials are challenging to prepare, but our property measurements indicate somewhat surprising physical properties. Our proposed neutron powder diffraction experiments will help us to understand the origins of these properties, and help us to design and prepare new functional materials with optimised properties.
DOI: 10.5286/isis.e.rb1820124
title: Ruthenium models of the [FeFe]-hydrogenase active site: seeking the terminal hydride

description: The [FeFe]-hydrogenase enzymes are some of the best catalysts know for generating hydrogen. We have an ongoing programme to understand how their chemistry works, and to replicate the core 'active site' of the enzyme. Recent literature reports have shown that replacing iron by ruthenium in the enzyme can allow isolation of a long sought 'terminal hydride' intermediate. Here, we will seek evidence that this intriguing compound can be seen by muon spectroscopy.
DOI: 10.5286/isis.e.rb1820168
title: Combined experimental and computational study on the influence of labelling on protein dynamics

description: IR labels can be used to study local environments in proteins in a site-selective manner. Neutron scattering experiments complement Raman and IR spectroscopy by delivering information about delocalized vibrational modes that might be vital for enzyme activity. Combining these experimental methods opens up new possibilities to better understand how proteins work. We want to investigate for the first time how IR labelling influences global protein dynamics of T4 lysozyme by using neutron scattering spectroscopy. The IR label itself has a distinct vibrational mode around 2160 cm^-1 that is sensitive towards the local microenvironment around the label. Density of state calculations based on molecular dynamics simulations predict changes in the 2-10 THz region upon labelling indicating changes in global dynamics. The TOSCA spectrometer allows us to observe both energy ranges at the same time.
DOI: 10.5286/isis.e.rb1820193
title: Magnetic correlation length measurements in Fe/Si multilayers using spin echo modulated small angle scattering

description: We wish to investigate the magnetic structure of a series of magnetic multilayers using a new technique we have successfully implemented called Spin Echo Modulated Small Angle Scattering. This is similar to SESANS and probes micron length scales. However as all the spin manipulations are performed before the sample we can use this for measuring magnetic correlation lengths and also using samples in high magnetic fields. We will investigate the magnetic structure of Fe/Si multilayers used in neutron polarising supermirrors. It is important to understand the in-plane magnetic structure in the magnetisation process for further improvement in the soft magnetic properties. Specifically the length scale of lateral correlations due to the fluctuating orientation of the spins in the layer would lead to a good understanding of the in-plane magnetic structure.
DOI: 10.5286/isis.e.rb1820251
title: Spin wave excitations in the 2D honeycomb ferromagnets

description: Graphene is the single layer of honeycomb-shaped carbon network, for which 2010 Nobel Prize in Physics was awarded thanks to its novel electronic properties. One of such novelties is the particles carrying an electrical charge but zero mass. In this work, we are going to investigate the quantum particles carrying magnetic field but zero charges on magnetic materials that have similar structures as graphene, namely CrI3 and Cr2Ge2Te6. In them, magnetic moments of Cr3+ ions align on honeycomb-shaped lattices and produce these "magnons" via cooperative oscillations. We will use inelastic neutron scattering method to observe the energy of such magnons as a function of neutron momentum transfer. We will be then able to estimate the bonding strength between electronic magnetic moments by analyzing the spectra, which may eventually reveal the existence of such massless magnetic particles.
DOI: 10.5286/isis.e.rb1820378
title: Sub-Kelvin helium confinement in crystalline nanopores

description: Under confinement in porous media, helium-4 excitations develop a complicate behaviour and, in addition to a bulk-like spectrum, a second branch emerges due to helium-4 atoms in proximity of the pore walls. These denser helium-4 layers support excitations that are known as 2D rotons because they are so far exclusively observed in the roton region, while they are predicted to exist at all wave vectors. We propose to investigate helium-4 confinement in the purely inorganic LTA zeolite by INS and in a helium-3 sorption insert. The great advantage of LTA is its crystallinity, combined with a relatively large surface-to-volume ratio. These characteristics will overcome the limitations encountered so far for the observation of helium-4 layer modes, i.e., disruptive surface morphologies and weak intensities. All the confining porous media investigated so far have amorphous surface morphology.
DOI: 10.5286/isis.e.rb1820468
title: Neutron Diffraction Strain Analysis of Ceramic Coatings from Suspension Thermal Spray

description: Liquid feedstock containing sub-micron to nano-sized particles is used in suspension thermal spray to produce nanostructured ceramic coatings with improved density, strength and durability over conventional powder based thermal sprayed coatings. It has already been demonstrated that suspension sprayed alumina provides two orders of magnitude wear protection compared to traditional high velocity oxy-fuel (HVOF) or atmospheric plasma sprayed (APS) coatings, and suspension HVOF sprayed Yttria stabilised zirconia (YSZ) coating has a better strain tolerance than APS coatings. The aim of this proposal is to investigate the residual strain behaviour of suspension high velocity oxy-fuel (SHVOF) thermal sprayed alumina and yttria stablised zirconia coatings deposited onto a CoNiCrAlY bond coat on a Ni-based superalloy (263) substrate.
DOI: 10.5286/isis.e.rb1820536
title: Investigating the internal structure of thermally annealed two-component polymer nanoparticle films for water processable OPV

description: The elucidation of the compositional profile of polymer:small molecule nanoparticle films is critical for applications such as water processable organic solar cells. In order to have efficient charge separation and transfer, a nanoscale morphology is needed. This is crucial as charge migration only occurs on length scales up to 10 nm, and if separation is larger than this charge recombination occurs, which has a substantial negative effect on overall solar cell performance. Therefore, it is important to see how the morphology of the nanoparticle films change post thermal annealing. Ideally the nanoparticles would melt after heating and maintain their blended interpenetrating nanoscale structure, however the polymer could migrate and form large domains which would hinder device performance. NR measurements would be able to confirm which blend films have optimal internal morphologies.
DOI: 10.5286/isis.e.rb1870014
title: Spin dynamics in pyrochlore Nd2Mo2O7

description: Most of Nd-pyrochlores show all-in-all-out long-ranged order ground state at low temperatures. Recently unconventional slow spin dynamics are reported in the paramagnetic state of pyrochlore insulators Nd2Sn2O7and Nd2Zr2O7. However, Nd2Mo2O7 reveals two-in-two-out spin ice like state at low temperature, and possesses delocalized electrons which may host novel phenomena associated with the interaction between the localized moments Nd3+ and the itinerant moment Mo4+. In particular, Nd2Mo2O7 exhibits unusual spin chirality. These motivate us to study the spin dynamics in Nd2Mo2O7 by mSR.
DOI: 10.5286/isis.e.rb1910121
title: MuSR study on spin liquid candidate NaYbSe2 with triangular lattice

description: The quantum spin liquid (QSL) is a long-standing attractive topic in condensed matter physics due to its tight relation to exotic properties such as high temperature superconductivity, topological orders and Mott insulators. Recently, YbMgGaO4 has been extensively studied and is believed to exhibit a QSL state. However, the spin dynamics in YbMgGaO4 may be due to the Mg/Ga exchange disorder, as suggested by a recent theoretical work. A large family of rare-earth chalcogenides AReCh2 (A=alkali or monovalent ions, Re=rare earth, Ch=O, S, Se) with rare earth ions forming triangular lattice has a simpler structure compare to YbMgGaO4 and removes the issue on possible exchange disorders in YbMgGaO4. We propose to perform ZF- and LF-μSR experiments on NaYbSe2 single crystals to understand the intrinsic spin dynamics of triangular lattice without disorder.
DOI: 10.5286/isis.e.rb1910277
title: MuSR study on a new superconductor: Pr3Cr10-xN11

description: A new superconductor Pr3Cr10-xN11 (Tc = 4.5 K) was discovered, and is potential candidate to host unconventional superconductivity. We propose to perform muon spin rotation/relaxation experiment,emts to study the superconductivity state of this compound.
DOI: 10.5286/isis.e.rb1910512
title: Formation and ammonia decomposition behaviour of lithium nitride hydride

description: Ammonia is seen as a key part of the transition to a sustainable energy economy, but needs decomposition catalysts to release its stored hydrogen. Lithium nitride-hydride (Li4NH) has been proposed to play a role in the catalytic decomposition of ammonia by non-stoichiometric lithium imide (Li2NH). Although Li4NH is a known decomposition product of Li2NH, it has yet to be observed under ammonia decomposition conditions. Here, we request three days of instrument time on the POLARIS diffractometer to investigate the role of Li4NH in this reaction by i) conducting an in-situ diffraction experiment on chnges to the structure of Li4NH under ammonia decomposition conditions, and ii) exploring the structural transformation between Li2NH and Li4NH by measuring in-situ diffraction data for the thermal decomposition of Li2NH to Li4NH under vacuum.
DOI: 10.5286/isis.e.rb1910518
title: Spin liquid state in a novel rare-earth based triangular lattice antiferromagnet NdTa7O19

description: Rare-earth based geometrically frustrated magnets represent a promising new platform for the search of enigmatic quantum spin liquids. Here, the entanglement of spin and orbital degrees of freedom is believed to be one of the crucial factors that can stabilize this disordered, yet highly quantum-entangled ground state. In our study, we focus on a novel triangular lattice antiferromagnet NdTa7O19, where such effects might take place. Our preliminary bulk magnetic characterizations indicate a lack of any magnetic ordering or freezing in this material. This prompts the need of more sensitive local-probe magnetic investigations that could unambiguously confirm the spin-liquid ground state and characterize the corresponding magnetic excitations. The muSR study performed far down to sub-kelvin temperatures should provide a valuable microscopic probe to confirm the  spin-liquid conjecture.
DOI: 10.5286/isis.e.rb1600054
title: Examining magnetic correlations and dynamics in the metallic non-collinear antiferromagnet Mn3Sn with inelastic neutron scattering

description: Non-collinear antiferromagnets are currently an area of much active research due to their potential use in creating robust spintronic and spin memory devices.  We have recently been carrying out in-depth studies of spin-waves (via inelastic neutron scattering (INS)) of various insulating non-collinear antiferromagnets such as (Y,Lu)MnO3, PdCrO2, and CuCrO2 to find unusual effects such as magnon-magnon and magnon-phonon couplings. Our immediate question is now how these effects change for metallic systems with noncollinear ground states. Mn3Sn is one such example with an antiferromagnetic ordering at 420 K, and, more importantly, has been recently found to exhibit anomalous Hall effect, which can arise from Berry's phase. In this proposal, we propose to study the spin dynamics by taking advantage of our large single crystal and understand the underlying physics.
DOI: 10.5286/isis.e.rb1610086
title: Inelastic neutron scattering study on the Spin-Lattice interaction in the Spinel Fe1+xCr2-xO4(x=0.2, 0.4, 0.6, and 1.0)

description: AB2O4 is one of the most investigated systems due to the interaction between electron, spin, orbital, and lattice, which lead to the anormal physical properties:a) the orbital ordering transition that originates from the localized B-site on a geometrically frustrated structure;b) the approach to the itinerant electron limit with decreasing B-B separation. Although various models have been proposed to explain the behavior, there is not yet a full consensus on the precise nature of the orbital ordering. FeFe2-xCrxO4 present an interesting property: the lattice constants are varied in the solid solutions of FeFe2O4 and FeCr2O4. In our previous study, the ground state should be decided by the competition of the itinerant electrons and the superexhange between A/B ions. In order to elucidate the complicated interactions, it is important to study the details of the dynamic response.
DOI: 10.5286/isis.e.rb1610134
title: Neutron spectroscopy of a series of Ruthenium triangles: a new possible route toward high-barrier molecular nanomagnets

description: Most of our technology is based on the use of charge, however the electron also has another less well-understood (or exploited) property called spin.  The application of this property in conjunction with charge, offers a range of new spintronic devices.  One of the most important of these applications is in data storage.  Molecular nanomagnets are materials with magnetic cores surrounded by an organic matter sheath.  These compounds have shown great potential for application in such very high-density data storage devices.  To realise this application the properties molecular nanomagnets still need to be suitably tailored.  A family of ruthenium-based nanomagnet triangles offer an example of a new approach being taken to obtain nanomagnets with the ideal properties.  Neutron spectroscopy can help us understand this new approach and guide future rational design of new molecules.
DOI: 10.5286/isis.e.rb1610298
title: SANS study on the aggregation behavior of aza-crown-water soluble conjugated polymers in solution and in films

description: Water-soluble conjugated polymers (WSCP) are an important class of materials which have received great attention as active materials in optoelectronic devices and in biosensing. The incorporation of the crown moieties into the polymer structure brings many advantages for the development of new sensing platforms. Crown compounds have been shown to selectively interact with cations. It is well known that the aggregation behaviour of WSCP in solution and in film is very complex. The formation of highly ordered supramolecular self-assembled structures is very important to attain a better morphology and optimise the performance of the device. This is possible through the formation of WSCP-surfactant complexes. The characterization of mesostructures in WSCP(surfactant) system in film is crucial to establish a correlation between the photophysical properties of the material and its morphology.
DOI: 10.5286/isis.e.rb1610324
title: Low Temperature Magnetic Properties of new Strontium(V) Ruthenate, SrRu2O6.

description: Layered strontium ruthenate materials are a prime example of how closely competing energy scales found in strongly correlated electron systems can give rise to a broad range of properties in closely related structures. Very recently a new strontium ruthenate (SrRuO6) has been synthesised for the first time. This material has attracted a lot of attention because it orders antiferromagnetically at very high temperatures (565K). This is in striking contrast with the behaviour observed in the previously known strontium ruthenates, which display a variety of electronic transitions (e.g. superconductivity, spin density waves, ferromagnetism) but always at very low temperatures. Following susceptibility measurements as a function of temperature and applied field, we have discovered an additional magnetic transition in the low temperature regime which we intend to study by neutron diffraction.
DOI: 10.5286/isis.e.rb1610417
title: Comparative Interaction Studies of Antimicrobial Agents on Floating Asymmetric Bacterial Membrane Models

description: The outer membrane (OM) of Gram-Negative bacteria (GNB) is an asymmetric structure which contains complex lipids known as lipopolysaccharides (LPSs) on the outer surface. LPSs comprise the membrane anchoring Lipid-A, the anionic core oligosaccharides and the very large, solution facing O-antigen which acts as a hydrophilic barrier to antibiotics. We have recently achieved an accurate model of the outer membrane using short chain LPS and now wish to start examining its interaction with antimicrobial peptides and proteins. These will include the antibiotic polymyxin, human innate immune peptide cathelicidin, LPS specific bacteriocin, colicin N and a beta defensin.
DOI: 10.5286/isis.e.rb1610487
title: Nematic spin fluctuations in tetragonal La2-xSrxCuO4

description: Uniaxial stress has been used to study the Fe-based superconductors with spectacular results. Both the transport properties and the low-energy magnetic excitations have been shown to respond uniaxial stresses. With pressure causing anisotropy to develop in the in-plane resistivity and in the spin excitations from the tetragonal state. In this experiment, we will apply the same technique to the high temperature cuprate superconductors.  These are thought to be mediated by spin fluctuations. We will determine whether "electron nematic" effects are present in the spin fluctuations of a canonical example, La2-xSrxCuO4. Nematic behaviour, may arise from an intrinsic tendency of the electronic system towards stripe formation or via coupling to the lattice.
DOI: 10.5286/isis.e.rb1620095
title: Phase Contrast & dark field neutron radiography using Larmor labelling

description: x-ray radiography is familiar to everyone who visits a dentist. Equally well known is that fact that x-ray radiography is not well suited to seeing contrast between different soft tissues in the body. The same problem occurs when x-rays are used to radiograph working devices such as fuel cells or batteries: some materials, such as water, simply do not provide enough contrast to be easily localized in a radiograph. Although neutron radiography solves this problem in some cases, it too is limited by the vagaries of neutron absorption contrast. We propose to develop a method that will allow neutrons to create an image based on different contrast mechanisms, including refraction and scattering from small imperfection. This will allow enhanced imaging and understanding of new materials and devices.
DOI: 10.5286/isis.e.rb1670520
title: Broken time reversal symmetry in the superconducting state in Sc5Ru6Sn18 probed by mSR
DOI: 10.5286/isis.e.rb1720034
title: The definitive Bi4Ti3O12: a textbook example of Hybrid-Improper Ferroelectricity

description: Bi4Ti3O12 is a well-known and studied layered perovskite; such phases are ferroelectrics, which have been used in random-acccess memories and other applications. Understanding the atomic-scale nature of the mechanism driving ferroelelctricity requires very careful and detailed crystallographic analysis, with powder neutron diffraction being the technique of choice. We undertook the first such analysis of Bi4Ti3O12 in 1999, using HRPD at ISIS. Since then, theoretical understanding in the field has moved on, and while our initial study is not 'incorrect' it is certainly 'incomplete'. We are now in a position to re-examine this material, using methods that have become available in recent years. Several possible distinct mechanisms of ferroelectricity in Bi4Ti3O12 that were not considered fully in the earlier work, will re-addressed and the full mechanism will be confirmed.