cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1820444
title: Tracking membrane dynamics during the topological phase transitions in amphiphile / water systems

description: The proposed experiment addresses the dynamics of surfactants in amphiphile/water systems during the topological transition, with a focus on the membrane with non-lamellae architectures, e.g. cubic phase . We here choose hexadecyl hexa(oxyethylene glycol) as the model system. With increasing temperature, it undergoes several topological states. Especially, it undergoes a hexagonal - cubic - lamellae phase transitions via heating while the cooling results a different lamellae-rhombohedral-hexagonal route. Though, the transition enthalpies are identical. Surfactant dynamics in 35ps time scale will be measured in all its topologies by using 17.4micro-eV resolution at IRIS. The results shall provides details on the dynamics in different membrane topologies, especially with peculiar information for the two intermediate states of the hexagonal-lamellae transition.
DOI: 10.5286/isis.e.rb1820610
title: μSR study of the magnetic ordering in the S=1 linear chain compounds RbNiCl3

description: The quasi 1-D magnets ANiCl3: A = Cs, Tl, order magnetically in two steps.  A partially ordered state between TN1 and TN2 and a fully magnetic ordered state below TN2.  RbNiCl3 has a crystallographic unit cell similar in size to TlNiCl3.  The radius of the Tl+ ion is a little smaller than the radius of Rb+ ion. However, RbNiCl3 orders only with one TN at1 T = 0K. We have a studied the magnetic ordering in CsNiCl3 and KNiCl3 via  muon spin relaxation behaviour.The complete the investigation of this series we propose to study the temperature dependence of the muon spin relaxation in TlNiCl3(TN1 =18.3K and TN2 = 12.5K). A similar study is proposed for RbNiCl3.  The temperature dependence of the muon spin relaxation will show if there is only one magnetic transition temperature. EMU data from the test experiment show the presence of 2 stopping sites. We request 4 days beam time on EMU.
DOI: 10.5286/isis.e.rb1870023
title: Probing Magnetic Order in Defective Reduced Graphene Oxides by Means of mu-SR

description: Reduced graphene oxide (rGO) with defective structure has shown interesting magnetic properties in the frame of room temperature ferromagnetism. The origin of the magnetic moments has been explained by NMR measurements originated from the existence of defects in the samples, not from possible impurities included in the system. Recent research has revealed that the increase of heating temperature and higher content of defects may enhance magnetization in the hysteresis curves. This may attribute to the change of defect in the rGO structure influencing the magnetic ordering in the sample. In the case of mu-SR study, the relaxation rate increased whenever the sample was exfoliated, indicating that the magnetic order was probably developed. Therefore, it is important to study and correlate between the possible magnetic ordering and the presence of defect in rGO samples by means of ZF mu-SR.
DOI: 10.5286/isis.e.rb1900005
title: Test of Neutron Effects On Commercial Off The Shelf FPGA

description: The goal of these joint ChipIR/VESUVIO proposed experiments is to characterize the SEU occurrence on new generation FPGA caused by neutrons. We will focus on a Commercial Off-The-Shelf (COTS) component, in order to evaluate its robustness and its potential use in space environment in particular for micro and nano satellites. Due to their weight, power and budget limitations, and their low altitude operation, these satellites commonly use high performance COTS components.FPGAs represent a very interesting solution for signal acquisition, processing and transmission in such satellites. In this frame, their susceptibility to neutrons is an fundamental issue. The main purpose of the experiment is to make an accurate diagnosis of what are the faults produced in very high density FPGA. This analysis could lead to the creation of a reliability model of the FPGA.
DOI: 10.5286/isis.e.rb1610305
title: Stress evolution of hydrogen charged duplex stainless steel under load

description: Duplex stainless steels have a microstructure composed of 50% ferrite and 50% austenite. This microstructure confers them high mechanical properties and corrosion resistance. For this reason, these alloys are widely used in subsea environments for gas and oil transportation systems. However hydrogen induced stress cracking is the cause of catastrophic failures in service. To quantify the hydrogen influence on the mechanical properties of duplex stainless steels, this study aims to compare the stress evolution, during constant load tensile testing, on two types of microstructures: forged and hot isostatic pressed duplex stainless steel, with and without hydrogen pre-charging. If successful a comprehensive understanding of hydrogen impact on mechanical properties of duplex stainless steels will be gained and used to further knowledge of the hydrogen induced stress cracking mechanism.
DOI: 10.5286/isis.e.rb1710184
title: Ion Binding in Tetradecyltrimethylammonium Surfactant Micelle Solutions

description: This proposal continues our studies of surfactant micelles using NIMROD, to obtain previously inaccessible details of headgroup-ion interactions. In our previous experiments using C10TA+ surfactants we found several unexpected results from our ion exchange and silica binding experiments. In the case of C10TA+ micelles with a para-toluene sulfonate counterion, we expected to see micele elongation due to binding and insertion of this amphiphilic counterion near the surfactant headgroups, however no elongation, or anion insertion was observed. In addition, when silica models were added to our C10TA+ micelles, we expected to see silica binding to the micelles as a first step towards formation of micelle templated silicas, and this was not observed. Possibly these observations arise from using such a short-chain surfactant. Here we wish to measure C14TA+ systems to check this hypothesis.
DOI: 10.5286/isis.e.rb1720115
title: Investigating the role of beta-phase morphology on deformation twinning in a two-phase Zr alloy

description: Zr alloys are used in cores of nuclear reactors because they are relatively transparent to neutrons, which helps the efficiency of a nuclear reactor. However, as any material also Zr alloys do slowly degrade in a nuclear environment. The way the material degrades depends on its microstructural characteristics, particularly how the crystals are orientated in the material. The crystal orientation is determined by the way the material is processed and it is the aspect of manufacturing parameters and microstructure evolution in Zr alloys we want to understand much better in order to develop modelling tools in the future to predict such things.
DOI: 10.5286/isis.e.rb1770008
title: Magnetic ground state in spinel titanates

description: The spinel titanates MgTi2O4 undergo the structural transition to the tetragonal phase. Since the displacement of the Ti ions has two-in two-out configuration, we consider the MgTi2O4 system as one of the candidate for the atomic-displacement-type ice. Below the transition temperature, the magnetic susceptibility decreases. Even in the Mg-substituted Mg1+xTi2-xO4, the reduction of the magnetic susceptibility is also observed in the cubic phase. It is still unclear whether the magnetic ground state is a spin-singlet state or not. We propose mSR experiment on Mg1+xTi2-xO4, and suggest to selecting key samples to clarify the magnetic ground state.
DOI: 10.5286/isis.e.rb1810025
title: WIDENING THE FRONTIERS IN FORENSIC PROFILING: PROBING BURNED HUMAN BONES WITH NEUTRON DIFFRACTION

description: Neutron diffraction techniques are applied to the study of burned human skeletal remains, for assessing heat-induced changes associated to alterations in bone´s microcrystallinity. The results, coupled to vibrational spectroscopy data (INS, Raman, FTIR), are expected to provide an improved understanding of the structural changes undergone by bone upon burning. A quantitative relationship between spectroscopic and diffraction parameters, dimensional variations and specific burning conditions is sought, with a view to relate burned to pre-burned parameters. This is an innovative way of tackling heat-induced changes in human bone, with a high impact in forensic investigation. This work follows successful experiments on MAPS and TOSCA, which were the first studies on human burned bones by neutron techniques and allowed us to identify spectral biomarkers of heat-elicited alterations [1].
DOI: 10.5286/isis.e.rb1810065
title: Water dynamics in dental zinc cement by quasi-elastic neutron scattering

description: Zinc phosphate cements (ZPCs) are used in dentistry. Cement formulation (liquid+solid) is largely empirical because of lack of information on the exact chemical nature of the amorphous product and on factors affecting ZPC microstructure. Characterization of the detected generic bound and unbound water populations, evolving in time, is absent, but its of great importance for understanding the development of the ZPC microstructure, and, consequently, the mechanical performance when in the mouth, the capacity to release/uptake fluoride, and dissolution rate. Our previous results showed that porosity develops because of segregation of the liquid component and that some gel-like material likely forms in time in the pores. With Quasi-elastic neutron scattering we want to characterize the evolution of the water populations dynamics in ZPC at two times, to help the design of more durable ZPC
DOI: 10.5286/isis.e.rb1810071
title: The effect of the onset of plastic deformation on texture in cast alpha-uranium.

description: Crystal plasticity numerical methods are being used increasingly to model the initiation and propagation of fracture in metals. These models can be more critically evaluated when applied to complex, anisotropic, crystal structures. To validate these models, experimental data are required that characterise the processes of deformation. We propose an experiment to measure the texture change that occurs with the onset of plastic deformation in cast alpha-uranium. This metal has an uncommon (orthorhombic) crystal structure, and exhibits a number of complex twinning systems. The twins are important because their localised shears can cause fracture initiation. We will compare the textures of undeformed and deformed material. The data will allow us to characterise the differences in the populations of twins, and will be compared with crystal plasticity simulations.
DOI: 10.5286/isis.e.rb1810133
title: Single crystal diffraction study of magneto-electric Er2BaNiO5

description: Er2BaNiO5 has been reported recently as a magneto-electric material, displaying a spontaneous polarization at T=55K, followed by a transition to a collinear antiferromagnetic state at 32K.  The structural displacement associated with the spontaneous polarization is reported to involve a displacement of the oxygen octahedral around the Ni ions.  We have prepared large high quality single crystals of ErBaNiO5 and we propose here to perform a structural study of Er2BaNiO5 around the ferro-electric and magnetic transition temperatures in order to directly observe the oxygen displacements and look for signs of magneto-elastic coupling.  We will require 2 days of beam time on SXD to complete this study.
DOI: 10.5286/isis.e.rb1810299
title: µSR study of centrosymmetric and non-centrosymmetric phase of HfRhGe

description: The field of non-centrosymmetric (NCS) superconductors has gathered much attention in recent years owing to its unconventional behavior. The lack of inversion symmetry in this compounds causes the splitting of Fermi surface due to antisymmetric spin-orbit coupling (ASOC), which leads to admixed spin singlet and triplet pairs making them exotic candidates for research. Most of the recent work in this field is directed towards the study of NCS transition metal compounds making them potential candidates over the NCS heavy fermion compounds where the strong correlation also plays a role. So it is important to pay much attention towards new NCS compounds which can provide ideas regarding mixed ground state in  NCS superconductors.
DOI: 10.5286/isis.e.rb1810520
title: Local structure of Sr-doped multiferroic bismuth ferrite

description: Bismuth ferrite, BiFeO3, is a much-studied ceramic showing both dielectric and magnetic ordering at relatively high temperatures. In order to improve its properties there has been much interest in doping BiFeO3, but rarely has there been structural characterisation of these materials. We have shown that it is possible to replace bismuth ions by strontium together with oxygen vacancies. Increasing composition of strontium lowers the transition temperatures so that the high-symmetry cubic phase becomes stable at room temperature. This is exciting because we cannot reach this phase by heating pure BiFeO3. We will use neutron total scattering with Reverse Monte Carlo analysis to study the local structure fluctuations in materials with various strontium compositions in both ferroelectric and paraelectric phases for comparison.
DOI: 10.5286/isis.e.rb1810713
title: Towards reliable residual stress characterization in dissimilar metal welds

description: The proposed experiment forms a part of a joint study by M. Rahman, an ILL PhD thesis student, and J. Brokx, a CDT thesis student supported by ISIS. In the proposed experiment, we intend to start the process of formalising the methodology for dealing with and ultimately quantifying the errors specific to determining residual stress in the microstructures typically found in dissimilar metal welds by simplifying the measurements with idealised samples. In particular, we plan to investigate the issue of pseudo-strains experimentally in association with voids and uneven distribution of large grains within a diffracting gauge volume. In addition, the experimental data will be used for the validation of the McStas simulation studying the pseudo-strain effects due to large grains or local texture.
DOI: 10.5286/isis.e.rb1810822
title: Ex-situ neutron powder diffraction studies of the impact of initial charging and discharging on Na-battery cathode materials

description: We request 2 days on WISH to study the changes in crystal structure and microstructure of a high energy-density Na-battery electrode material in the first charge/discharge cycle.. Our principal objective is to understand the significant changes in the cathode crystal structure and particle morphology that occur during the first charge/discharge cycle.
DOI: 10.5286/isis.e.rb1810865
title: Controlling Amphiphilic Nanostructure in Amino Acid Ionic Liquid Solutions

description: In these experiments we will investigate how the liquid structure of mixtures of biocompatible ionic liquids (salts with melting point that are liquid near room temperature) with simple organic compounds  changes with composition in order to understand how to design better solvents for a wide range of applications.
DOI: 10.5286/isis.e.rb1820112
title: Novel skyrmionic spin textures in non-chiral magnets

description: Magnetic skyrmions are topologically protected objects that exist in the spin texture of certain magnetic materials. We have shown that muon spin relaxation is a powerful technique for studying the physics of skyrmions and related magnetic textures. Here we propose to extend our investigations of skyrmions to two new recently observed skyrmionic states of matter that are topologically distinct from conventional skyrmions, biskyrmions in NiMnGa, and antiskyrmions in the Heusler alloy Mn1.4Pt0.9Pd0.1Sn. This work will enable a broader understanding of the dynamics of skyrmionic spin textures and help push the field closer to practical applications in spintronics devices.
DOI: 10.5286/isis.e.rb1820174
title: MuSR investigations of spin-chain oxides Sr4-xCaxMn2CoO9, a magnetoelectric and single-ion-magnet

description: The  spin-chain systems are interesting for various fascinating phenomena such as geometrical frustration, single-ion-magnetism, spin-gap, etc. Recently, it is observed that spin-chain can also favor magnetoelectric (ME) coupling, though, the mechanism is not clearly understood. The spin-chain oxide Sr2Ca2CoMn2O9 exhibits long-range magnetic ordering and strong ME coupling. However, the compound Sr4CoMn2O9 (where Ca is fully replaced by Sr) exhibits single ion magnetism (SIM) without LRO, though  ME coupling is still present. This is rare in literature. The proposed µSR investigation (2-50 K) in zero-field and longitudinal field of 40 kOe will enable us to understand the nature of magnetic ground state and detail spin dynamics; which in turns will help to understand the mechanism of ME coupling and the significant role of non-magnetic ions (i.e. Sr/Ca concentration) on complex magnetism
DOI: 10.5286/isis.e.rb1820201
title: Negative-thermal expansion in ScF3 studied using muon-fluorine entanglement

description: ScF3 is a material with the ReO3 structure which shows negative thermal expansion.  This experiment will use implanted muons to create an F-mu-F state in this structure and then follow this spectroscopically to measure the change in the muon fluorine bond length, and F-mu-F bond angle, as a function of temperature. Our experimental data will be complemented by detailed "DFT+\mu" calculations carried out by fixing the lattice constant to different values to simulate the effect of temperature.This experiment could open up the use of the muon more widely in investigating local structural (or even quantum) effects in materials with unusual thermal expansion properties.
DOI: 10.5286/isis.e.rb1820260
title: Examining the topological nature of superconductivity in PdTe2

description: PdTe2 was found to be superconducting below Tc = 1.7 K and a Type-II Dirac semimetal. A protected bulk Dirac point arises from a band inversion that occurs within the Te p-orbital manifold, and is induced by a naturally disparate out-of-plane dispersion of pz and px/y-derived bands along kz direction. Spin-ARPES measurements reveal that the surface states are strongly spin polarized (&gt;70%). STM and heat capacity studies give no indication of nodes in the superconducting order parameter or of in-gap states. The helical spin polarization of the surface states and the apparent s-wave superconductivity suggested from thermodynamic measurements present a dichotomy and raises a promising prospect to whether superconductivity has also a topological nature. With the aid of muSR, we will look for the proposed exotic superconductivity and possible time-reversal symmetry breaking in the sample.
DOI: 10.5286/isis.e.rb1900004
title: Magnetic Hamiltonian of the S=1/2 kagome antiferromagnet Cd-Kapellasite

description: In everyday life, we often experience frustration from not being able to reach our goals; similarly, in physics and chemistry, frustration is caused by the inability of a system to satisfy all of its internal interactions. Frustration is most commonly observed in magnetic materials, where it is caused by either the geometry of the magnetic lattice or competing interactions. These systems are predicted to manifest many interesting phenomena, most notably exotic states called a quantum spin liquids. In this proposal, we aim to study the magnetic excitations of candidate for such a state, Cd-kapellasite. While the material shows conventional long range order at zero magnetic field, frustration stabilises a number of unusual quantum states in a field. To understand these, we need to understand the internal interactions of the system, for which we request beam-time on the LET spectrometer.
DOI: 10.17632/fbtfpkvjj6.1
title: Data for: Weak and Strong Hydrogen Interactions on Porous Carbons Materials in High-Temperature Systems

description: Weak and Strong Isotherm data collected for eight amorphous carbon materials
DOI: 10.5286/isis.e.rb1710193
title: Residual strain measurement in suspension based thermal sprayed nanostructured alumina coatings

description: Suspension and solution precursor (SSP) spraying is an emerging thermal spraying technology which utilises liquid feedstock containing sub-micrometre and nanoparticles. Alumina (Al2O3) is a widely used engineering ceramic and it has excellent dielectric and tribology properties. 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 coatings. In this proposal, through thickness neutron diffraction (at ENGIN-X) residual strain measurement is proposed using the vertical scan mode. This is the first study on residual strain measurement using neutron diffraction of a suspension sprayed coating. Two coatings sprayed at 72 kW and 101 kW flame energy will be provided by the investigators and their high temperature behaviour will be investigated.
DOI: 10.5286/isis.e.rb1720089
title: Chasing the hydrogen-saturated defects in tungsten with Muon spectroscopy

description: The structure and dynamics of hydrogen (H) defects in tungsten recently become a topic of major interest since this metal has been chosen as shielding material for the next step fusion device ITER.With the help of muon spin relaxation and rotation, which are not limited by the dilution of H, we plan to explore samples specifically prepared with proton irradiation or Si/W ion implantation to have different damage profiles in terms of mono-vacancies and larger clusters.Ultimately, the object of our study is to obtain further understanding of the location of H and of its behaviour in tungsten, starting from low temperatures, where a static muon will mimic H trapped in materials' defects, up to several hundred degrees, where dynamics will take place after the release of H from the trapping sites.
DOI: 10.5286/isis.e.rb1800065
title: Understanding the molecular origin of cononsolvency

description: The term cononsolvency has been used to describe a situation in which a polymer is less soluble in a mixture of two cosolvents than it is in either one of the pure solvents. If we move into the field of protein stability, then it becomes a desirable feature the fact that the protein become collapsed or, better said, folded in a certain solvent mixture. Cononsolvency is thus closely related to the suppression of protein denaturation by stabilizing osmolytes. Cononsolvency behaviour has been found even for small amphiphilic molecules dissolved in methanol/water mixtures. Using a combination of Raman-MCR spectroscopy and MD simulations, it was shown that TBA aggregation is more pronounced in the mixtures than in either of the pure solvents. A thorough structural investigation of TBA solutions is proposed to help the interpretation of thermodynamic and spectroscopic data.
DOI: 10.5286/isis.e.rb1810000
title: Local Investigation of Quantum Phase Transition in Reduced Dimensions by muSR

description: Quantum phase transitions (QPT's) are phase transitions that are driven by zero-temperature quantum fluctuations, and are accessed by varying a non-thermal control parameter. Matter near a QPT shows unconventional features, like a non-Fermi-liquid behaviour. The magnetic QPT occurring in the metallic NixPd1-x alloy system across the quantum critical point (xc = 0.026) is one such example, wherein signatures of quantum criticality have been observed in bulk macroscopically, and microscopically using 54Fe time-differential perturbed angular distribution technique. Further, matter in reduced dimensions shows many quantum-physical properties dissimilar to bulk. It would, therefore, be quite intriguing to explore QPT in NixPd1-x nanoparticles. In the present proposal, we would like to perform such studies of quantum criticality and NFL behavior locally using muSR.