cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1810784
title: Investigation of shake-down effects on residual stress redistribution in ship structures

description: The fact that residual stresses are redistributed or relaxed during operations shows the importance of understanding residual stress after a particular period. Elastic shakedown is a phenomenon in which the structure undergoes plastic deformation accompanied with a change in residual stress during the first few cycles followed by an elastic response. As a consequence, residual stresses are redistributed or relaxed. The principal aim of this experiment is to investigate the initial, as-welded distribution of residual stresses and their relaxation as a result of shakedown in T-joints. Dh-36, a typical ship structural steel is used to manufacture T-joints based on ship welding standard. This project has chosen an industrially relevant sample and load levels owing to the fact that these contribute to the variation in residual stress redistribution.
DOI: 10.5286/isis.e.rb1810004
title: A SANS Study of Hierarchical Order in DNA Complexes with Trojan Peptides

description: We will use SANS to investigate the nanoscopic structure  i.e., sizes in the range 2-200 nm  of complexes formed by cell-penetrating peptides and nucleic acid species. The hierarchical structure spans a wide range of lengthscales and a wide q range is required. Contrast variation in H2O/D2O will be performed to isolate scattering from the peptide and nucleic acid components in the complexes between so-called Trojan peptides and plasmid DNA. The Trojan peptides to be employed include the Tat-HIV segment GRKKRRQRRRPPQ and Penetratin sequence RQIKIWFQNRRMKWKK.
DOI: 10.5286/isis.e.rb1810041
title: Energy dependent, sample transmission correction for time-of-flight diffraction data normalisation from hydrogenous materials

description: Diffraction from hydrogenous materials is complicated by the large incoherent scattering contribution from hydrogen. For many materials the solution is to deuterate before performing neutron experiments. However, for many materials this is not possible, due to incomplete deuteration, cost and/or the fact that deuteration changes the structure and phase transitions that are of interest. For time of flight methods, the situation is further complicated by the fact that the hydrogen incoherent scattering cross section is energy dependent, therefore, sample transmission is energy dependent. This proposal aims to investigate and quantify the effect for well known hydrogenous materials as a function of sample path length, temperature and hydrogen content to generate empirical curve(s) that can be used in reduction of hydrogenous diffraction data for the suite of instruments at ISIS.
DOI: 10.5286/isis.e.rb1810086
title: Micellization in H/F-Carbon surfactant mixtures used in fire-fighting foams

description: The aim is to probe the micellar compositions of fluorocarbon/ hydrocarbon mixtures used in commercial fire-fighting foam formulations (Figure 1) using contrast variation SANS. These fluorocarbon surfactants have already been studied individually and as F/F-surfactant mixed systems (Figure 1) and now will be studied as F/ H-surfactant mixtures within a typical range of compositions commensurate with a fire-fighting formulation.  The data will allow us to understand how the surfactant aggregation is affected by mixing to provide new understanding on the colloidal properties of these practical surfactants. This is the third stage in a new 3-year program, including SANS, so that F-carbon surfactants can be replaced by more environmentally-responsive low-F or hydrocarbon analogues. Chris Hill is a 3rd year PhD student fully funded by fire-fighting technology company Angus Fire.
DOI: 10.5286/isis.e.rb1810343
title: Local magnetism and magnetoeletric effect in TbMn0.98Fe0.02O3 studied by muon SR

description: TbMn0.98Fe0.02O3 is an interesting multiferroic material, as the partial substitution of the Jahn-Teller active Mn3+ cation by the non-Jahn-Teller active Fe3+ has remarkable effects on the magnetic structure and on the electric polarization. This proposal aims at resuming the first experiments on muon SR in TbMn0.98Fe0.02O3, vs temperature and applied longitudinal magnetic field, to unravel magnetic fluctuations and disorder, and to study the effect of a static electric field on the coupling between ferroelectricity and magnetic ordering. This proposal is the second step towards a comprehensive muon SR study in this compound, involving the application of strong electric fields. By joining the muon SR results with those obtained from other techniques, we expect to disentangle the complexity and origins of the local magnetic fields, disorder and fluctuations, and magnetoelectric coupling.
DOI: 10.5286/isis.e.rb1810583
title: Obtaining Quantum Critical Signatures of the Spin Liquid Phases in 1T-TaS2

description: The system 1T-TaS2 is a charge density wave (CDW) insulator below 180 K that has one residual spin 1/2 for every 13 Ta atoms in the modulated CDW structure.  These spins and their surrounding structural modulations are arranged in a triangular lattice and the spins have been shown by muSR to remain dynamically fluctuating down to 70 mK, which is consistent with a quantum spin liquid (QSL) ground state. Previous ZF muSR and NQR studies have indicated a crossover between two QSL regimes taking place around 55 K, however the nature of these two phases is not yet established. We propose to characterise these two QSL states using a recently developed muSR technique that combines ZF and LF measurements to derive quantum critical exponents associated with the two phases. The results will be compared with those we have obtained on other QSL systems that show similar crossovers with temperature.
DOI: 10.5286/isis.e.rb1810611
title: Exploring Local Ion Diffusion Dynamics in Na-doped Li5+2xLa3-xNaxTa2O12 by Muon Spin Relaxation

description: A grand challenge facing society today is the need to develop green energy technologies. For instance, as we increase our use of renewable energy sources to cut our consumption of CO2-producing fossil fuels, we must be capable of efficiently storing the energy such sources provide for when demand is high. Li-ion batteries, for example, are widely employed as portable energy storage devices. However, safety concerns surround the liquid electrolytes currently utilised in commercially available Li-ion batteries. An important question, therefore, is whether new solid electrolyte materials can improve the safety and performance of solid-state batteries. Here, we propose to study the candidate solid electrolyte material, Li5La3Ta2O12, and explore how doping its structure with sodium ions affects its electrolyte function using muon spin relaxation measurements.
DOI: 10.5286/isis.e.rb1810814
title: µSR studies of the superconducting and magnetic properties of FeSe1-xSx

description: FeSe1-xSx is an important model system for investigating the relationship between superconductivity and nematicity. The nematicity can be suppressed systematically by the isovalent sulphur substitution which vanishes completely at x = 0.17. Here, we propose to expand our previous work on single crystals of FeSe by studying single crystal samples of FeSe1-xSx (x = 0, 0.1, 0.17, 0.2, 0.25) and investigate the evolution of the superconducting gap structure as a function of sulphur doping x, namely the strength of nematicity. We also propose to investigate magnetic instabilities which arise in the nematic state and observe their evolution in FeSe1-xSx (x = 0, 0.1, 0.17, 0.2, 0.25) as a function of sulphur doping from the zero-field µSR measurements. We ask for 13 days of MUSR beamtime with 3He and 4He cryostats to complete this proposal.
DOI: 10.6073/pasta/c4b2d3e148ad802f330450d2c90682f2
title: Soil Particle Size Analysis at Permanent Quadrat locations, Jornada Experimental Range, 2001

description: This completed dataset, collected in 2001, contains soil particle size
  analysis (PSA) and sand fractionation data from soil cores collected
  at 116 quadrat locations that are part of the Jornada Experimental
  Range's long-term Permanent Quadrats study. The goal of this effort
  was to help characterize plant-scale factors related to vegetation
  dynamics observed in the Permanent Quadrats. At each quadrat location,
  4 cores were collected at 2 depths (0-5cm and 5-20cm) and assessed for
  percent sand, silt and clay. The sand fraction, if large enough, was
  then separated into 5 sand size classes (53-106 micrometers, 106-250
  micrometers, 250-500 micrometers, 500-1000 micrometers, 1000-2000
  micrometers) to measure the percent fraction of each.
DOI: 10.25912/5ca3eed161916
title: Plasma OzID data
DOI: 10.5286/isis.e.rb1720209
title: Phase diagram of a switchable dielectric framework near the critical point

description: The family of hybrid Prussian blue analogues includes many electroactive materials, where organic cations moving within the pores of the cyanide framework cause unusual and exploitable electrical properties. Our target material, (HIm)2K[Fe(CN)6], has a large dielectric constant in its two high-temperature phases due to the rotation of imidazolium ions in its cubic pores. The transition between these two phases affects the cation dynamics drastically, but itself depends on the unit cell parameter, varying from first-order to critical or even supercritical. We propose here to study this phase transition as a function of pressure. Mapping the phase space of this system will help to establish the link between its structure and the particular cation dynamics that correspond to desirable electrical properties.
DOI: 10.5286/isis.e.rb1810076
title: Solid state phase transformations at very high temperature in a martensitic stainless steel

description: Selective Laser Melting (SLM) is a technique of Additive Manufacturing of metallic parts. There are still several barriers of acceptance of that process in the industry and particularly the lack of understanding of microstructures of materials obtained. One of the most common materials used in SLM is the stainless steel named 17-4PH. However examination of this material after SLM shows a very unexpected microstructure. In this proposal we plan to study the phase transformations in that material at very high temperature (i.e. above 1400°C, just below the melting point) using neutrons diffraction in ISIS/HRPD with in-situ specimen heating. This study will allow better understanding of the microstructure and properties of stainless steel parts obtained from SLM.
DOI: 10.5286/isis.e.rb1810111
title: Tuning the skyrmion lattice phase by Mn doping in the Co-Zn-Mn series

description: Magnetic skyrmions are vortex-like objects characterised by an integer topological winding number. They have been observed in the spin structures of several magnetic materials and it was recently demonstrated that skyrmions can be stabilised at and above room temperature in members of the the beta-Mn-type Co-Zn-Mn series. The discovery of skyrmions in this system is important as it shows that the SL can be stabilised at or above room temperature and that this phase can be tuned by changing the Mn doping concentration in the CoZn matrix. We have recently demonstrated that muSR is a promising method for exploring skyrmions and their slow dynamics. Here we propose to complement our investigation of the slow dynamics in bulk Co8Zn8Mn4, along with our related thin film measurements, by measuring additional compositions of the Co-Zn-Mn series.
DOI: 10.5286/isis.e.rb1810280
title: Exploring the rigidness of PDMS star polymers using SANS

description: Hairy particle has been attracting general interest from mechanical engineering, bio-materials, and physics. Various theories that have been developed to describe their solution behaviors and rheological/mechanical properties of their bulk materials, are still under debating. The major issues that hinder the clearly understanding of hairy particles are their purities and the lack of the knowledge of their structures. A group of well-defined, mono-dispersed nanoparticles have been applied to build a novel group of hairy particles. CV-SANS is a powerful technique that can be used here to probe the polymer arm conformation, the polymer chain packing density, and the distribution of invasive solvents.
DOI: 10.5286/isis.e.rb1810339
title: Catalysis  in Hydrogen-Bond Rich Porous Organic Materials

description: Hydrogen bonding (H-bonding) interactions are essential in biological and chemical processes, particularly in reactions catalysed by enzymes and small-molecule catalysts. Enzymatic processes are highly depend on the properties of the reaction environment, such as pH, presence of ions, organic solvents, and other proteins in cell media. Characterization and rationalization of relevant H-bondings in active sites is critical in designing and synthesizing new system. Given that confined space of such organic materials is rich in H-bond donors and acceptors, the aim of this proposal is to obtain an insight into the role of H-bonding interactions between the NH3 molecules and the organic porous material using neutron scattering spectroscopy. Following this first step, this research will be extended to the incorporation of enzymes into the peptide-based porous organic polymers (PAAs, PIs).
DOI: 10.5286/isis.e.rb1810665
title: Determining the role of inversion symmetry in single crystals of the noncentrosymmetric superconductor La7Ir3 by µSR.

description: In superconductors, the inversion symmetry of the crystallographic structure plays a central role in the formation of the Cooper pairs. When inversion symmetry is broken, there is the possibility of a mixing of singlet-triplet pairing, leading to unconventional superconducting properties.La7Ir3 is a noncentrosymmetric (NCS) superconductor where time-reversal symmetry (TRS) breaking below the superconducting Tc is observed in polycrystalline samples. We have successfully grown the first single crystals of La7Ir3. We propose to use muons to study the anisotropy of the superconducting properties of La7Ir3, investigate the influence of magnetic fluctuations, and search for TRS breaking. To the best of our knowledge, this would be the first time TRS breaking is studied in a single crystal of a NCS superconductor where TRS breaking is observed in samples in the polycrystalline form.
DOI: 10.5286/isis.e.rb1810678
title: Measuring stoichiometry in the lithium amide-imide solid solution with negative muons

description: Variable stoichiometry is a defining feature of the function of lithium amide-imide (LiNH2-Li2NH) as a highly-active ammonia decomposition catalyst and a solid state hydrogen store. While the existence and importance of the solid solution is known, quantifying the precise stoichiometry is challenging, hindering efforts to obtain a clear understanding of stoichiometry-dependent properties in the system. In this continuation proposal, we seek to build on our successful demonstration of the use of X-ray spectra from negative muon decay as a means of quantifying the stoichiometry of lithium amide-imide samples. We request 5 days on Port 4 at RIKEN to use a higher-resolution low-energy X-ray detector and an improved experimental setup to enable the precise and accurate determination of the stoichiometry of a wide range of lithium amide-imide samples.
DOI: 10.5286/isis.e.rb1810715
title: High Pressure Structure of Carbonic Acid

description: Recent published studies have identified a stable solid form of carbonic acid at high pressure. This proposal is for beamtime to collect the data to solve its crystal structure.
DOI: 10.5286/isis.e.rb1810749
title: Detecting Weyl Fermion in TaAs via Neutron Scattering

description: Weyl semimetals possess novel properties protected by the topology rather than symmetry. With enormous theoretical work searching for new Weyl semimetals, experimental research for these materials caught more interest recently. Currently, experimental work is mainly focused on transportation and angle-resolved photoemission spectroscopy (ARPES) to discover and identify topological materials. We propose an inelastic neutron scattering on TaAs, a typical 3D Weyl semimetal without magnetism, to detect the electron-hole scattering between Weyl nodes.
DOI: 10.5286/isis.e.rb1720052
title: Understanding the spin-Peierls Transition in KTCNQ and derivatives

description: Motivated by work showing that magnetic coupling between TCNQ anions in potassium TCNQ (KTCNQ) can be changed simply by changing the aromatic substituents, we seek to qunatify this behaviour. This can be achieved by different levels of fluorination on the quinodial ring and we would study the series TCNQ, TCNQF, TCNQF2 and TCNQF4, where there is an increasing number of F atoms substituted on the ring through the series itself. There has already been shown to be a shift between the muon-radical hyperfine coupling between TCNQ and TCNQF4 however more work is needed to be able to understand how this shift varies and whether we can in fact control the distrobution of spin density across the molecule. It is hoped this will then provide vital infomation as the the non-linearity of the way the transition temeprature depneds on F substitution.
DOI: 10.5286/isis.e.rb1720144
title: Emergent Magnetism in Ferroelectric Thin Films

description: Reports on conductivity, superconductivity and magnetism at atomically precise interfaces between non-magnetic insulating oxides have sparked intense research on emergent phenomena. We have recently demonstrated robust high-temperature magnetism in perovskite oxide ferroelectric films sandwiched between an insulator and a metal. Our macroscopic results and model calculations suggest that the observed magnetic response is due to the accumulation of screening charges within the ferroelectric film. A verification is vital to solidly prove that magnetisation does exist, the magnetic layer is indeed located inside the ferroelectric film, and the magnetisation is independent of the chemical composition of the materials used. A key requirement is the determination of the magnetisation depth profile in the heterostructure. Polarised neutron reflectometry constitutes the ideal technique for this.
DOI: 10.5286/isis.e.rb1720462
title: Observation of low energy modes of adsorbed CO on a catalyst

description: Carbon monoxide occurs widely in industry in many roles. It is a feedstock for methanol synthesis and in Fischer-Tropsch chemistry for synthetic petrol and diesel. It is a pollutant from partial combustion of fuel and it is a potent poison of low temperature fuel cells. The metal-to-carbon stretch and deformation modes of adsorbed CO on a catalyst should be very informative as they provide direct information on the adsorbate-catalyst interaction. These modes are difficult to observe by conventional spectroscopy as they occur in the 500-800 cm-1 region, that for a typical catalyst is inaccessible. INS should be able to observe these modes, but to date all INS catalysis experiments have used hydrogenous adsorbates in order to take advantage of the large cross section of 1H.The aim of this proposal is use the enhanced sensitivity of TOSCA to observe the low energy modes of CO on Raney Cu.
DOI: 10.5286/isis.e.rb1810207
title: Phonon-liquid electron-crystal behaviour in copper-rich tetrahedrites

description: Tetrahedrites are minerals which consist largely of earth-abundant and environmentally-friendly elements (copper and sulfur), and are attracting much interest due to their potential for thermoelectric energy recovery. Tetrahedrites are one of the best p-type thermoelectric materials known to date, due to their extremely low thermal conductivity. We have recently shown that in copper-rich tetrahedrites, copper becomes mobile above 120 degrees centigrade, and this has a marked influence on the thermoelectric behaviour of these materials. Here, we seek to gain a better understanding of the effect of copper ionic mobility on the lattice thermal conductivity and the vibrational phonon modes of this interesting class of materials.
DOI: 10.5286/isis.e.rb1810257
title: Crystalline electric field excitations in the triangular-lattice rare-earth selenide

description: The rare-earth compound KYbSe2 provides a new chance for the study of frustrated magnets with strong SOC. It resembles YbMgGaO4 in many ways. Our susceptibility and specific heat measurements have revealed an effective spin-1/2 ground state with strong magnetic frustration in this compound. Moreover, in KYbSe2, there is no site mixing problem in the non-magnetic layers which is suggested to give rise to a broadening in crystalline electric field (CEF) excitations as observed in YbMgGaO4. Therefore, by measuring the CEF excitations in KYbSe2, we can unambiguously determine the ground state along with the intrinsic symmetry which are closely related to the SOC interaction.
DOI: 10.5286/isis.e.rb1810316
title: Tuning the Luttinger liquid state in copper pyrazine-based spin chain systems

description: The ability to manipulate quantum states of matter is a goal of condensed matter science. Recent progress in molecular magnetism has shown the potential for gaining control over the structural building blocks of materials in order to engineer quantum magnetic properties. Our muon measurements have proven particularly important in demonstrating how such structural variation influences magnetic exchange pathways. Recently we showed how the systematic tuning of the interlayer separation in a two-dimensional molecular system affects its magnetic properties. Using this insight, we now seek to systematically vary the low-dimensional superexchange pathways in a class of tuneable one-dimensional materials in attempt to gain control over the spin Luttinger liquid state. We propose here to determine the ordering temperatures and probe the 1D dynamics of two novel spin chain materials.
DOI: 10.5286/isis.e.rb1810391
title: Characterization of compositional, morphological and microstructural features of four South and Southeast Asian bronzes through TOF ND

description: Four sculptures from the Rijksmuseum South- and Southeast Asian collection are proposed for investigation by means of neutron diffraction to complete the characterization of composition and microstructure started with neutron tomography analysis performed on CONRAD II at HZB. The Rijksmuseum, in collaboration with CNR, is applying neutron methods of analyses to this group in order to gain information on their manufacturing and conservation status, and to demonstrate that traditional destructive sampling is not always necessary for gaining metallographic and compositional data. Data gathered are expected to provide information on regional techniques and materials used by the artisans, thus supplementing art-historical assumptions, which are in many cases not supported by scientific evidence.
DOI: 10.5286/isis.e.rb1810594
title: Tracking spring-type motions in inorganic helices

description: Materials with helical and double helical structure motifs are prone to display fascinating spring-type behaviour, i.e. a shallow energy surface along the spring-axis in which low-energy vibrations can occur. Recently SnIP has been reported, the first purely inorganic material in which a double helical structure is observed. Quantum chemical calculations reveal a shallow energy landscape with regards to compression and elongation along the helices of the structure. We here propose an inelastic neutron scattering experiment to access the spring-like low-energy vibrations in the materials with the general formula SnXP with X = Cl, Br and I.