cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1720261
title: Elucidating deformation mechanisms in micro-alloyed FeCoCrNi high entropy alloys via in situ neutron diffraction

description: We have carried out two beamtimes to elucidate the deformation mechanisms of FeCoCrNi based high entropy alloys(HEAs) with single FCC phase using neutron diffraction, first at room temperature then at 77 K, determining the stacking fault energy (SFE) and confirming the occurrence of twinning-induced plasticity. Now we propose to continue to study deformation mechanisms in HEAs using in situ tensile tests. First we want to carry out the tests at ultra-low temperatures (10 and 40 K) on the FCC single phase HEAs, which will allow us to measure SFE across different temperatures. Secondly, we want to perform the tests on three new FeCoCrNi HEAs micro-alloyed with C, Al and Mo with a duplex structure (FCC+BCC), in order to determine the stress partitioning between the two phases. The results will be of significance for HEA design making full use of micro-alloying effects.
DOI: 10.5286/isis.e.rb1720362
title: Residual Stress Measurements of Laser Deposited IN718 by Neutron Diffraction

description: There is increased motivation in the aeroengine industry to extend the service life of high-value components by developing new repair technologies for previously unrepairable components, removing the need for replacement or remanufacture.  Laser deposition is being increasingly used within the engineering sector to repair high-value components that have been damaged in-service to extend their life and economic operation. This work will form part of a project to develop a validated FE model of the laser deposition process that can be applied to the repair of aeroengine components, allowing parametric investigations to be carried out and optimum repair strategies to be determined without the need for lengthy experimental trials.  The objective of this proposal is to measure the residual stresses in two IN718 laser deposition samples on thick IN718 plates to validate the developed FE model.
DOI: 10.5286/isis.e.rb1720489
title: Exploring Divalent Ion Mass Transport in Polar Solids with μSR

description: Batteries are ubiquitous in everday applications but making them cheaper, safer, and able to store more energy could widen their use still further. Many rechargeable batteries rely on lithium ions moving backwards and forwards between a material that contains lithium to graphite through an electrolyte. Being able to replace the graphite with lithium metal would massively increase the energy density, but unfortunately defects form that make such a battery unsafe. Other metals are not prone to such defects and among them magnesium shows promise because it allows a metal anode and carries two units of electrical charge on each ion. This means a magnesium-ion battery could have a dramatically higher energy density than any lithium-ion battery, while remaining safe and potentially cheaper. Here we want to investigate how magnesium moves through a candidate material for such a battery.
DOI: 10.5286/isis.e.rb1720503
title: Density dependent deviations from hydrodynamic diffusion in a molten salt

description: The study of binary ionic liquids and, as their prototypes, molten alkali halides, has a long tradition in theory, experiment as well as simulation. According to Fick's law the driving force for diffusion is a concentration gradient and can be described by a Lorentzian line with k-dependent line width which is proportional to the wave vector squared. However, detailed investigations on monatomic liquids already demonstrated that there exist deviations  for the diffusion process on atomic length scales.Here we want to demonstrate that the same mechanism apply for a binary melt.
DOI: 10.5286/isis.e.rb1769001
title: Influence of chemical pressure on the helimagnetic and skyrmion lattice correlatations and magneto-crystaline effects in Mn1-xFexSi

description: The recent discovery of skyrmions and skyrmion lattices in materials with no inversion symmetry and their corresponding potential applications of Skyrmions in magnetic information storage and processing devices has increased the scientific interest in these chiral materials. The archetype chiral system is MnSi, on which various studies have been performed. The question remains what the influence is of applying chemical pressure in the form of Iron doping in MnSi. Earlier measurements show the existence of two QCP in Mn1-xFexSi. However, it remains unclear what exactly happens to the phase diagram under field, the (chiral) magnetic correlations and fluctuations present in MnSi if chemical doping is introduced as well as to the crystaline effects and relaxations observed for MnSi. To answer these questions, we propose to study Mn1-xFexSi with x = 0, 0.08 and 0.10 with SANS on LARMOR.
DOI: 10.5286/isis.e.rb1769002
title: Corrections to SESANS in hydrogenous systems in time of flight

description: We want to use a technique which allows us to probe materials at length scales which cannot be easily accessed by other techniques called SESANS. This allows us to look at structures on the nm to micron length scales. Recent experiments have shown that in order to investigate materials that contain hydrogen we need to make additional corrections. Many of the samples which we would like to look at such as foods, plastics and biological samples do contain hydrogen. Hence we would like to perform a series of experiments in specially designed samples which either contain no hydrogen or a controlled amount of hydrogen. By doing this in a systematic way we will be able to understand how to disentangle changes from hydrogen from our investigations and allow us to look into these materials with a greater definitude.
DOI: 10.5286/isis.e.rb1800001
title: Magnetic ground state of Ho3CrGa4O12: A promising low temperature magnetocaloric material

description: Solid state magnetic refrigeration is a viable alternative to cooling using increasingly scarce liquid helium. A good magnetocaloric material in this temperature regime would have: a) suppressed or no magnetic ordering b) high change in magnetic entropy c)  optimum performance in low fields attained by a permanent magnet, eliminating the need for cryogens. The frustrated Ising garnet, Ho3Ga5O12, satisfies these criteria. We find partial Cr3+ substitution in Ho3Ga5O12 leads to a dramatic increase in magnetocaloric performance. We propose this is due to changes in the magnetic ground state in Ho3CrGa4O12. Neutron data above 2 K shows no ordering features; the susceptibility shows a broad feature at 0.7 K. We aim to carry out neutron scattering measurements down to 0.05 K to determine the magnetic ground state and model the key magnetic interactions and magnetocaloric effect in Ho3CrGa4O12.
DOI: 10.5286/isis.e.rb1800005
title: Study of gas absorption in MCM41.

description: We have studied the absorption of nitrogen gas in MCM41 on NIMROD at a pressure of 1 bar and at temperatures to 87K (A K Soper and D T Bowron, Chem. Phys. Lett., DOI: https://doi.org/10.1016/j.cplett.2017.03.060, 2017). The data were analysed with EPSR using a model of dense amorphous silica for the substrate. The results demonstrated that scattering data of this kind can be used to give a very direct and accurate estimate of the pore-sizes in these materials. We observed two layers of nitrogen and were able to model the data accurately with EPSR. The new proposal intends to extend these earlier measurements to lower temperature to observe capillary condensation and model the structure of the nitrogen in the fully absorbed state. In addition we would like to study the absorption of some other common gases, oxygen, hydrogen and methane which have important technological applications.
DOI: 10.5286/isis.e.rb1810066
title: A Structural Study of Tungsten Tellurite Glasses

description: Tungsten Tellurites are being used to make optical fibres that transmit light into the mid infra red.  However, not much is know about the structure of these glasses. We wish to better understand the interaction between tungsten atoms and the tellurite glass network.  The aim is to relate structural changes arising from the addition of tungsten oxide to functional properties, such as Tg, density and refractive indices.   The good sensitivity of neutrons to tungsten, tellurium and oxygen will enable all the short range correlations in the glass to be measured with equal weighting. When combined with X-ray correlation functions and anomalous x-ray correlation functions at the W K-edge (time applied for I15 diamond), it will be possible to characterise the tellurium-oxygen and tungsten-oxygen environments to be characterised by extracting bond lengths and coordination numbers.
DOI: 10.5286/isis.e.rb1810104
title: Lipid exchange between high density lipoprotein (HDL) and model phosphatidylcholine membranes: the effect of unsaturation and cyclic species

description: Lipoproteins are the main carriers of lipids in the body. HDL is believed to favor cholesterol removal and decrease the risk to develop atherosclerosis and related cardiovascular diseases. Impact of the results. We have developed protocols to understand lipid exchange between lipoproteins and model membranes using neutron reflection. We have studied the exchange processes between HDL and saturated lipids as well as a natural extract, in the presence and absence of cholesterol. Surprisingly, the presence of cholesterol has little effect on lipid exchange but the natural extract behaves significantly different than the saturated lipids. Here we plan to clarify whether this effect is due to the presence of unsaturations, the presence of cyclic structures or the complexity of the lipid mixture in the dPC extract.
DOI: 10.5286/isis.e.rb1810638
title: Characterisation of layered double perovskite electrode materials for Solid Oxide Fuel Cells using neutron diffraction

description: The research on new anode materials for solid oxide fuel cell is extremely important for its potential to overcome the drawbacks of current state of the art anodes. In this experiment, beam time is sought for newly synthesized Layered double perovskite-type oxygen deficient materials (LnBaMn2-xMoxO5+d and LnSrMn2-xMoxO5+d (Ln = Nd, Pr, Gd, x = 0.0, 1.0). Initial x-ray diffraction/ electrical characterization on these materials is very promising. This proposal requests 2 days beam time on Polaris to perform RT diffraction on six samples along with in-situ experiment studying conductivity during the diffraction experiments as a function of temperature on two of the best performer samples in this series under dry Argon atmosphere. The outcome of this in-situ experiment will provide us a deeper understanding of the structure-property relationships within these new electrode materials.
DOI: 10.5286/isis.e.rb1820136
title: Local Structure in Tetragonal Tungsten Bronze (Sr,Ba)Nb2O6 Uniaxial Relaxor Ferroelectrics

description: Oxides with tetragonal tungsten bronze (TTB) structures are an important class of ferroelectrics with properties relevant for several technological applications.  The interactions between the chemical disorder and local polar atomic displacements that control the ferroelectric response of TTBs remains uncertain.   The proposed experiments aim to determine the local structure in a representative TTB  using neutron total scattering and other data, with a goal of getting a better insight into the structure-property relations in these materials.
DOI: 10.5286/isis.e.rb1820182
title: Ionic and electronic conductors  the magnetic structure behind cathode materials for Li-ion batteries

description: Ni rich layered oxides are promising cathode materials for Li-ion batteries since they fulfil the energy density requirements of the automobile industry but they tend to degrade relatively fast. The magnetic and electronic properties of the materials have been under discussion since their discovery, though this knowledge is essential to understand their functionality and the reasons for failure upon long-term operation. Although previous powder neutron measurements have not detected any long range order in LiNiO2, a semi-disordered cluster model has been proposed based on high field magnetisation measurements. Here we propose to use the greater sensitivity of the Wish diffractometer combined with high quality single crystals to observe either magnetic diffraction from long range ordered moments or diffuse scattering from correlated magnetic ions.
DOI: 10.5286/isis.e.rb1820189
title: Adsorption of NADH at the electrode/electrolyte interface under electrochemical control

description: This proposal concerns the adsorption behaviour of a key electron-transfer species, NADH, found in many cells as well as in bioelectrochemical devices used to capture light energy, on two important electrode surface typesglassy carbon and stainless steel. We are particularly interested how the structure of the adsorbed species changes upon variation of applied potential, with the ultimate aim of improving understanding of the electron transfer mechanisms at these interfaces. Previous electrochemical measurements have implied that NADH molecules may behave rather interestingly and change their adsorption structure (e.g. flat vs standing upright, monomer adsorption vs dimer) depending on both the solution conditions and applied potential. Neutron reflectometry offers a unique opportunity to verify (or contradict) these hypotheses.
DOI: 10.5286/isis.e.rb1820243
title: Water structure in C-A-S-H by neutron diffraction with isotopic substitution: insights into the hydration properties of low CO2 cements

description: The manufacture of every ton of cement emits approximately 0.8 tons of CO2 into the atmosphere, comprising 57% of the global human-made CO2 emissions. A low pH - low CO2 class of alkali activated materials consisting of a nanoscopic phase of an Al-substituted C-S-H, called C-A-S-H, is one of the most promising replacements of traditional cementitious binders. C-A-S-H has improved durability and strength properties, as well as environment-friendly character (slag recycling and reduced CO2 emission). However, very little is known about the atomistic structure of C-A-S-H and the structural and dynamical properties of water within its pores. Here, we propose to use the information gained from a recent study on the structural properties of different C-S-H pores in order to understand how the presence of Al substitutions affects the structural properties of water in the different C-S-H pores.
DOI: 10.5286/isis.e.rb1820339
title: Proximity Effect in Fe3O4:Pt Multilayers

description: The spin Seebeck effect is a newly discovered phenomenon that if harnessed, could result in a significant improvement of the efficiency of thermoelectric energy generators. Spin polarised neutron reflectivity will provide us with complementary measurements that enable determination of the spin polarisation of the film as well as surface sensitive magnetic ordering and disorder at the interface. This is especially important as the influence of the interface (i.e. the magnetic proximity effect) is still not well understood. We plan here to obtain complementary measurements to resonant magnetic x-ray reflectivity (XMaS, ESRF) to determine the change in proximity effect from a metallic to insulating state in Fe3O4:Pt bilayers.
DOI: 10.5286/isis.e.rb1820467
title: Residual stress stability in Laser Shock Peened Aerospace Components with Crystallographic Texture

description: It is well known now that the compressive residual stresses produced using surface treatment like Laser Shock Peening (LSP) are beneficial in improvement of the fatigue life of structural materials. The residual stress field obtained after surface treatment is used in the design process to improve factor of safety and fatigue life of the materials. However, this entire process works on the assumption of stable residual stress field in the service life of the treated component, which is inaccurate. In this experiment, we are investigating the stability of LSP residual stresses in aircraft components under fatigue loading. We will measure the relaxation of residual stress in textured aluminium alloy before and after fatigue loading. The measurement will allow us to develop a meso-scale model of residual stress relaxation in engineering components.
DOI: 10.5286/isis.e.rb1820509
title: Nanoarchitecture of folded maltose binding protein hydrogels

description: Proteins are the workhorses of the cell, performing a huge array of functions from providing mechanical strength to molecular recognition & binding. They perform these functions due to their specific, well-defined and evolutionary optimized folded structures. We are interested in their potential as building blocks for functional biomaterials. Our goal is to develop a cross-lengthscale understanding of the physics of folded protein networks, specifically in chemically cross-linked protein hydrogels. SANS measurements will provide essential information on the structure of our gels, and will be vital in bridging the structural/mechanical information from computational modelling to the mechanical insight from rheological measurements. This study will deliver (i) crucial benchmarking of our simulations (ii) structural information to guide our future applications of these novel biomaterials.
DOI: 10.5286/isis.e.rb1820567
title: Measurement of Mechanically Induced Residual Stress Field on Conventional Fracture Specimen

description: This project focuses on the development of new numerical modelling techniques for fatiguecrack growth and in particular, non-uniform crack front evolution and crack growth throughcomplex, through-wall residual stress profiles. Ultimately, the aim of the combined numerical-experimental research programme is to improve guidance in existing codes and standards (e.g. R6 and BS 7910) to reduce the potential over-conservatism of fracture mechanics andfitness-for-service assessments.
DOI: 10.5286/isis.e.rb1900117
title: Single-event characterization of 7-nm technology node using neutron beam at ChipIR

description: Semiconductor industry is currently offering 7 nm technology node with FinFET fabrication processes. Soft error causing mechanisms and error rates for FinFET technologies are expected to be vastly different from those for planar technologies. This proposal is for the investigation of neutron-induced soft errors for 7 nm flip-flop and logic circuit designs. We will be using custom-designed test ICs containing multiple hardened and non-hardened FF designs and logic circuits. Since soft errors caused by neutrons are going to dominate all other failure mechanisms, tests are needed to estimate neutron-induced failure rates to allow for development of predictive models. Results from these experiments will be supported with radiation transport simulations and circuit simulations. Results will support a dissertation and will be disseminated through publications at conferences and journals
DOI: 10.5286/isis.e.rb1910120
title: Muon Spin Relaxation Study on a honeycomb lattice H3LiIr2O6

description: Quantum spin liquid (QSL) state is a state in which the spin degree of freedom doesnt freeze even at absolute zero temperature, but entangles with each other in a long distance. QSL has attracted lots of attentions due to its potential application on quantum information and its relation to the mechanism of high temperature superconductors in recent years. Recently, a new compound H3LiIr2O6 has been discovered to be a candidate of QSL. However, physics in H3LiIr2O6 is not clear so far and more efforts are needed and further details should be clarified in the experiments. We propose to perform ZF- and LF-μSR experiments on H3LiIr2O6 to study the possible Kitaev type spin liquid state.
DOI: 10.5286/isis.e.rb1910136
title: Muon spin relaxation study on superconducting CaBi2 with a non-trivial Fermi surface topology

description: In recent time a significant effort has been devoted to Bi-based compounds for being potential candidates of topological insulators. Similarly,  a number of investigations also concentrate on finding new topological superconductors. In this quest, we have discovered a novel superconductor CaBi2 with critical temperature Tc = 2.0 K. Remarkably, very recently by means of ARPES study, we have observed the existence of Dirac point in this system. However, until now, no microscopic experiment has been carried out to characterize the superconducting ground state in CaBi2. We, therefore, propose to carry out rigorous µSR study on this sample using the MUSR spectrometer at the ISIS facility.
DOI: 10.5286/isis.e.rb1910171
title: Melanins vibrational behaviour as a function of temperature and hydration to give insight to its heat capacity and conductivity behaviour

description: Electroceuticals is the attempt to speak the electrical language of the nerves to achieve higher treatment effect. Thus, the search is on to develop devices to enhance personalised healthcare. Part of creating such devices is selecting materials that  can interface between biology and computers. One such material is the skin pigment melanin since it is bio-compatible and sustains electrical current. Recently we obtained electrical and heat capacity measurements (as a function of hydration and temperature) on melanin that showed unusual low temperature behaviour. The implications are that there are physical structural differences between hydrated and dry melanin, which changes its electrical conduction. We wish to use inelastic neutron scattering to probe the structure of hydrated melanins via its vibrational spectra and correlate it to our previous measurements.
DOI: 10.5286/isis.e.rb1910246
title: Study of unconventional superconductivity in YFe2Ge2 using muon spin rotation and relaxation measurements

description: In the layered iron-based superconductor YFe2Ge2, a high Sommerfeld ratio of order 100 mJ/mol K^2 and a T^3/2 temperature dependence of the electrical resistivity at low temperature indicate strong electronic correlations and point towards an unconventional pairing state. Theoretical proposals for the superconducting state include s+- or triplet pair wavefunctions and there are striking structural and electronic similarities to some of the iron pnictide superconductors. Microscopic studies of the superconducting pairing state by muSR have been held back by the lack of high quality, bulk superconducting samples without ferromagnetic alien phases. We are now able to grow single crystals with a bulk Tc of about 1.1 K and RRR &gt; 130. With this new generation of crystals, muSR measurements can produce a step advance in our understanding of the superconducting pairing state in YFe2Ge2.
DOI: 10.5286/isis.e.rb1910350
title: Insights into the structure of mechanochemically-synthesised ternary lithium halides LiAlX4 (X = Cl, Br and I) by total scattering

description: In the current work, we study inorganic solid-state electrolytes for lithium-ion batteries. These materials, unlike the traditional liquid electrolytes, could lead to a breakthrough in battery lifetime and safety, since the use of flammable organic solvents is no longer needed. Our aim is to study the ways in which the ionic conductivity can be tuned. We propose to perform PND studies to obtain a definitive model of the crystal structure, on a series of LiAlX4 (X = Cl, Br, I) samples, in parallel with a complementary, variable-temperature dynamics experiment on MuonSR. This data will be crucial for gaining insight into the structure-conductivity relationships.