cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1810029
title: A total scattering study of the phase transitions in the hybrid organic-inorganic photovoltaic methylammonium lead bromide

description: Hybrid organic-inorganic perovskites are interesting candidates for a range of applications, from solar cells to light emitting diodes and lasers. For the latter applications the properties and efficiency are highly dependent on the morphology and particle size. Here we intend to characterise the temperature depedent phase behaviour of a fully deuterated sample of CD3ND3PbBr3 in bulk form. This will allow the influence of strain induced effects related to particle size to be investigated through modelling techniques. Our previous neutron studies have revealed that the published bulk phase behaviour is incomplete and we intend to correct this. A full understanding of the changes in the hydrogen bonding of the methylammonium cation with the perovskite framework as a function of temperature is likely to be of general interest for all applications of this family of materials.
DOI: 10.5286/isis.e.rb1810311
title: Investigating short-range nematic correlations in paradigmatic iron-based superconductors

description: Iron-based superconductors possess an unusual property known as electronic nematicity, in which electrons spontaneously choose a preferred direction. The nematic state and its fluctuations are thought to be related to the superconductivity, but much remains unknown. We propose to use pair distribution function analysis of neutron scattering data to study short-range structural distortions arising from nematic fluctuations in two archetypal families of iron-based superconductors, BaFe2(As,P)2 and Fe(Te,Se). The results will provide rich information about nematic fluctuations, including their extent in temperature and composition space, their length scale, and their magnitude.
DOI: 10.5286/isis.e.rb1810513
title: Liquid phase self-assembly of semiconductor nanoparticles for photon multipliers

description: Our research aims to develop plastic films that change the colour of the light that passes through them, not by absorbing certain wavelengths of light, as a simple colour filter would, but by converting light of one wavelength to another without losing any energy. Such a film, applied to a silicon solar cell, could make it up to 30% more efficient. To do this we need to make semiconductor nanocrystals, coat them with a very thin layer of an organic semiconductor so the two materials are in molecular contact. Then we have to disperse these tiny composite nanoparticles in a clear plastic film, as evenly as possible and without clumping. Small angle neutron scattering allows to pick out the shapes of the composite nanoparticles and their component parts, and the way they interact each other, helping us to design routes to make these "photon multiplier" films.
DOI: 10.5286/isis.e.rb1810562
title: Lattice dynamics in magnetoelectric HoMnO3

description: The manipulation of magnetic properties electronically is of great importance in modern computing. Current technology uses electric currents which draws a relatively large amount of power. An alternative scheme uses electric fields to control the magnetic properties via the magnetoelectric effect and this could reduce energy dissipation by as much as a factor of 100. One promising material is HoMnO3. Here, an applied electric field distorts the crystal structure, changing the magnetic interactions and consequently the magnetic state. To understand these properties and design materials with improved performance it is necessary to understand the coupling between them. We aim to measure the structural excitations in HoMnO3 and by combining this with careful modelling understand this coupling with implications for the design of future materials.
DOI: 10.5286/isis.e.rb1810573
title: Real space elemental analysis using negative muon capture

description: The disordered relaxor ferroelectrics display exceptional dielectric properties including record braking piezoelectric coefficients.  One of the unique properties of these systems is that they display a distinct skin effect where the surface displays different properties over the bulk.  One possible explanation for this is due to a chemical inhomogeneity that results from diffusion or other surface related effects.  To investigate this, we propose to use negative muon capture to investigate the relative concentration as a function of depth in the sample.  The proposal will ultimately test the possibility of using this technique for investigating relative elemental and ionic concentrations in the material.  Potentially, this technique could be used to test industrial samples without the need for destroying the material to apply XAFS or EDX techniques.
DOI: 10.5286/isis.e.rb1810879
title: Neutron Diffraction Analysis of the Crystallography of Early Scientific Instruments

description: Early scientific instruments are typically made of latten, a quaternary copper alloy (Cu, Zn, Sn, Pb) with many trace elements. The crystallographic structure depends on the metalworking techniques used in their manufacture.Ongoing research into the history and development of the instruments requires profiles of the elements.(to be established in a parallel negative muon proposal) and information on the crystallography. This proposal is to extend existing neutron diffraction techniques to this different material to provide structurel information on three selected archaeological specimens being profiled in the muon experiment, This will both extend the proven capability of the technique and give a more complete description of the specimens and their history.
DOI: 10.5286/isis.e.rb1820052
title: Investigation into the Effect of Heating Rates on Recrystallisation Mechanism in Electrical Steels

description: Electrical steels (ES) used in motors and transformers. The major challenge is to optimise the magnetic property of ES to reduce energy waste during service. The crystallographic texture of ES is a key component in governing magnetic performance. Here, an experimental study is proposed to correlate the processing conditions and annealing parameters that affects the texture. In general, heating rate, annealing temperature/time, and cooling rate are the main parameters that can influence the texture. However, the effect of heating rate on the magnetic property is yet to be thoroughly investigated. It is in industrial and academic interests to take this fundamental study further; analysing the effect of heating rate as well as the degree of deformation on the final property of ES. Here, we aim to provide insight into current understanding of recrystallisation and texture evolution in ES.
DOI: 10.5286/isis.e.rb1820128
title: Searching for novel quantum magnetic excitations in the lacunar spinels

description: Spin liquid is the quantum state of matter in which magnetic moments change their orientations just like atoms in liquid change their positions.  Since magnetic fields due to electrons are a two dimensional entity existing in three dimensions, they exhibit novel dynamical behaviours that classical physics cannot explain. We are investigating the possibility of spin liquid formation and associated quantum dynamics in GaB4Se8 (B = V, Nb, Ta). In these lacular spinels, four magnetic B ions collectively form a tetrahedron like a molecule. Each tetrahedron has one unpaired electron, which interacts with surrounding tetrahedra via quantum mechanical Coulomb force. Although the interaction is measured to be quite strong, no relevant bound state has been explicitly observed. It offers a possibility for the spin liquid state, which we will use neutron scattering method to look for.
DOI: 10.5286/isis.e.rb1820144
title: Understanding the role of spin orbit coupling on superconductivity in ScMX (M = Ru, Rh and Ir; X = Si, P)

description: It is a great interest of research to explore the superconductivity in 111-family superconductor with strong spin orbit-interaction. In this proposal we wish to investigate role of spin orbit coupling in the newly discovered ScRuSi (ortho), ScRhP and ScIrP. ScRuSi (ortho), ScRhP and ScIrP exhibits superconductivity between 2 and 3.4 K. Using Ginzburg-Landau formula upper critical field is estimated to be HC2 = 0.87 T, 0.5 T and 5 T for ScRuSi (ortho), ScRhP and ScIrP respectively. Specific heat jump was found to be  1.55 and 1.23 for ScRuSi and ScIrP respectively. In this proposal we want to investigate microscopic superconducting properties of ScRuSi (ortho), ScRhP and ScIrP using transverse field, zero field MuSR measurements.
DOI: 10.5286/isis.e.rb1820161
title: New brownmillerite-based oxide ion conductors: Local structure and structure-property relationships

description: Oxide ion conductors are key components in a number of technologically important applications. Our research programme on the development of new oxide ion conductors, using neutron scattering methods in conjunction with computational modelling, has resulted in new insight into the relationships between structure, dynamics and properties in some of the leading solid electrolytes. Crucially, we have been able to demonstrate the importance of variable coordination environments of cations and the rotational freedom of these polyhedra in facilitating high oxide ion mobility at low temperatures. We have recently prepared new excellent oxide ion conductors based on the brownmillerite Sr2ScGaO5. They have a disordered local structure and we therefore request 3 days of POLARIS beamtime for neutron total scattering experiments on the new materials to  elucidate structure-property relationships.
DOI: 10.5286/isis.e.rb1820402
title: Molecular interactions in amorphous paracetamol

description: The appearance of multiple crystal forms is one of the bottlenecks in pharmaceutical formulation. To date the result of a crystallisation experiment cannot be predicted and we do not understand the influence of the amorphous phase (solution or melt) on the crystal form. A lot of attention has been paid to crystallisation from solution, which is currently the standard method in industry, whilst crystallisation from the melt has been widely neglected. However, this crystallisation pathway frequently leads to unique crystal forms that are not accessible through any other route. In this proposal we want to measure the melt phase of paracetamol, which presents the only path to obtain the metastable form III. By using SANDALS to obtain total scattering data and connected EPSR simulations, we will connect the molecular interactions in the melt with those in the crystal structure.
DOI: 10.5286/isis.e.rb1820463
title: Spin dynamics and magnetism in CeRh6(Ge1-xSix)4

description: In Ce-based heavy fermion materials, there is competition between the interactions which lead to a magnetically ordered arrangement of the Ce magnetic moments, and the hybridization between the local moments and conduction electrons, which quenches the local moments and gives rise to a non-magnetic ground state. Sometimes the magnetic transition can be tuned to zero temperature at a quantum critical point (QCP), where unusual properties arise due to quantum fluctuations. CeRh6Ge4 orders magnetically at a low temperature of 2.5 K, but by swapping Si for Ge, the magnetism is suppressed and eventually disappears, likely at a QCP. We propose to examine a series of these doped compounds using muon-spin relaxation so as to characterize the magnetically ordered state, examine how the magnetic state changes as it is suppressed, and to probe the spin fluctuations near the possible QCP.
DOI: 10.5286/isis.e.rb1820625
title: Deposition of lipid bilayer through peptide-discs

description: We are developing a new protocol for the preparation of lipid bilayers suitable to host membrane proteins with control on their orientation. Our proposed strategy is based on anchoring the membrane proteins re-constituted in nanodiscs to the support surface. Peptide-discs are nanodiscs where a lipid bilayer is surrounded by a belt of self-assembled peptides, which can easily be removed by buffer rinsing. As first step toward the development of this new protocol first of all we propose to understand the fundamentals of peptide-discs mediated lipid bilayer formation. During a preliminary test, we have verified by NR that peptide-discs can be used to form a POPC bilayer. Here we propose NR measurement to assess the reproducibility of this system and to test the effect of different lipid composition on the peptide-disc deposition.
DOI: 10.5286/isis.e.rb1900100
title: OX6 - Measurements of single-event burn-out of HV power devices for different technology nodes

description: Measurements of single-event burn-out of HV power devices for different technology nodesHigh-voltage power semiconductor devices, such as IGBTs, diodes and MOSFETs are susceptible to destructive failure due to terrestrial cosmic radiation (CR), notably the nucleon part. As a consequence, device development has to ensure adequate radiation hardness for every device technology. This aim can only partly be met by device and technology simulations and, therefore, also calls for extensive device tests. In order to reduce testing times accelerated irradiation tests at facilities with a nucleon energy spectrum close to the natural terrestrial CR are essential. The thus obtained failures rates will be compared to simulation predictions and storage tests.
DOI: 10.5286/isis.e.rb1520029
title: Magnetic order in the spin-ladder iron oxyselenide BaFe2Se2O

description: In this proposal we request time on WISH to study the crystal structure and long range magnetic order on cooling, and the short range magnetic order above TN in an unusual iron oxyselenide BaFe2Se2O. This spin-ladder material is a Mott insulator that is related to the Fe-based superconductors. As such, understanding the magnetism will give an insight into the nature of the magnetic exchange interactions and underlying physics of these systems.
DOI: 10.5286/isis.e.rb1520467
title: Interaction of Antimicrobial Silver Nanoparticles with Eukaryotic and Prokaryotic Model Membranes.

description: Silver nanoparticles have been shown to have strong antimicrobial effects against many organisms, including those resistant to conventional antibiotics. However, the exact mechanism of action remains controversial. In particular, the factors controlling specificity of these interactions are not known. In this experiment, we will examine the interaction between anionic or cationically coated NP's with both eukaryotic and prokaryotic membrane mimics, in order to better understand the factors affecting the initial membrane interaction with both membrane types.
DOI: 10.5286/isis.e.rb1610143
title: In-situ neutron powder diffraction study of the synthesis of Half-Heusler thermoelectric materials

description: XNiSn (X = Ti, Zr, Hf) Half-Heusler materials are potential candidates for application in thermoelectric waste heat recovery. The aim of the experiment is to follow the formation of these compounds from elemental precursors using neutron powder diffraction. This will shed light on how these solid state reactions proceed. This information is important as the synthesis of phase pure samples of these materials remains challenging.
DOI: 10.5286/isis.e.rb1610195
title: Detailed Structural Characterisation of Functional Spinel Materials

description: We propose to use neutron scattering to examine the complex structures of some new mixed oxide materials that have applications in catalysis and for their magnetic properties. The materials all have a common crystal structure, the spinel structure, but they contain various levels of structural disorder and are formed as nanocrystalline powders. This means that total scattering experiments are needed to provide data to build models that include short-range disorder and long range crystal order. Neutron scattering is required since the large extent of data will provide high-resolution data for modelling and also allow mixtures of metals to be distinguished and modelled properly. By building models for the the structures of the materials we aim to understanding their properties, being measured in parallel work.
DOI: 10.5286/isis.e.rb1610257
title: Possible Spin-Pierls transition in double-perovskite Ca2InOsO6

description: Osmates in the perovskite-like structure are very topical. For example, recent discoveries include Slater transitions, and "ferroelectric-like" structural transitions. These arise because of structural distortions, geometric frustration, magnetism and strong spin-orbit coupling. Owing to our recent experiments on Pb2CaOsO6, we have been motivated to re-examine the isostructural material Ca2InOsO6, which shows bulk magnetic properties very similar to the archetypal Spin-Peierls system CuGeO3. Motivated by this, we wish to perform low temperature neutron diffraction on Ca2InOsO6 in order to determine if the system truly displays a non-zero magnetic moment, and if there is a substantial modulation of the structural parameters coincident with the phase transition at 14K.
DOI: 10.5286/isis.e.rb1610397
title: High energy spin excitations in SrCo2As2

description: the correlation degree in 122 iron pnictides mainly depends on the electronoccupancy of each orbital and that by doping electrons the correlation decreases monotonically. This is also suggested by ARPES results where the electronic band width of BaCo2As2 is clearlylarger than that in Ba 0.6K0.4Fe2As2. In our previous inelastic neutron scattering experiment on SrCo2As2,the (1/2,1/2) spin excitations were found to persist up to 135 meV and not to split as that in BaFe2As2 in whichtwo peaks can be clearly seen above 75 meV. This is a clue that the magnetic dispersion is indeed hardenedin SrCo2As2 as the magnetic correlation decreases. However, it is not clear whether the spin excitations will split and disperse to zone boundary at higher energ , or simply be more diffusiveand disappear at (1/2,1/2) point. Furthermeasurements on improved SrCo2As2samples are necessary.
DOI: 10.5286/isis.e.rb1610470
title: Further study of high pressure magnetic order and superstructure in BiNiO3 at low temperatures

description: Transition metal oxides make up a remarkable group of materials, exhibiting a wide variety of unusual electronic and magnetic properties. They have generated much interest, in particular since the discovery of high temperature superconductivity in the layered cuprates such as La2- xSrxCuO4. BiNiO3 is weakly antiferromagnetic at room temperature, and becomes a metal if it is pressurised. If the sample is cooled under pressure a new phase is seen which is poorly understood. The aim of this experiment is to verify the structure of this new phase, and its behaviour under pressure, and to determine if the sample retains its room temperature magnetic structure.
DOI: 10.5286/isis.e.rb1700019
title: Interaction of amino acid based biosurfactants with model lipid bilayers

description: N-acyl amino acids are surfactants with attractive applications in different technological fields. They are referred to as mild surfactants because they are commonly considered less irritant and safer than sulfates anionic surfactants. N-acyl amino acid surfactants could infact represent an alternative and safer option to SDS. However, the full potential of such surfactants remains unexplored, mainly because of the lack of information regarding a full characterization of their physicochemical and toxicological properties, including their interaction with biological membranes. With the aim to use these compounds as drug delivery agents, we propose here to study the interaction between N-decanoyl amino acid surfactants and supported lipid bilayers prepared by liposome deposition. This study will help us better understanding and proceeding further in their application in real systems.
DOI: 10.5286/isis.e.rb1710011
title: Doping of Dion-Jacobson phases with quantum magnetic ground states

description: Dion-Jacobson (DJ) [layered perovskites A'[An-1BnO3n+1], where A' is an alkali cation, A is an alkaline earth or rare earth cation and B is a transition metal) have a wide range of functionalities. (CuCl)LaNb2O7 behaves as a system of ferromagnetically coupled Shastry-Sutherland quantum spin singlets. We have prepared Dion-Jacobson layered perovskites (CuCl)La1xSrxNb2O7 (x = 0, 0.1 and 0.15) via topotactic ion-exchange reactions with intermediate compounds RbLa1xSrxNb2O7. Replacing some La3+ ions with Sr2+ ions in the perovskite precursor is expected to disrupt the quantum singlet state and perhaps lead to a transition from insulator to metallic behaviour. High resolution powder neutron diffraction data are required to discover how Sr-doping affects the orthorhombic superstructure and whether any magnetic order emerges at low temperature as a result of dimer-breaking.
DOI: 10.5286/isis.e.rb1710127
title: Structure and thermal expansion of a recovered high-pressure polymorph of ammonia dihydrate

description: In our high-pressure studies of candidate outer solar system minerals using PEARL, we have observed a number of high-pressure polymorphs of ammonia dihydrate, some of which have proved amenable to indexing and structure solution, occasionally with the aid of constrained ab initio structure prediction. However, one of these, ADH IV, has evaded structure solution; the most likely reason for this is that the indexing is not correct. A recent STFC grant has allowed us to build a high-pressure device and liquid-nitrogen recovery system, allowing us to synthesise these hard-to-solve high-pressure phases and quench them to ambient pressure below 100 K. We propose to do this with ADH IV and exploit the high resolution of HRPD for indexing, powder structure solution and high-precision measurement of the thermal expansion tensor.
DOI: 10.5286/isis.e.rb1710232
title: Superconductivity and static moments in LuxZr1-xB12

description: Nonmagnetic impurity substitutions impact on superconducting properties in various ways depending on the pair-breaking mechanism. The aim of the proposed experiment is to understand the effect of such substitutions in ZrB12, a dodecaboride superconductor, and to test a recent suggestion [N. E. Sluchanko et al. Phys. Rev. B 93, 085130 (2016)] that static magnetic moments can be induced by non-magnetic impurities.  We have carried out some preliminary measurements at PSI which confirm that Lu-substituted ZrB12 is an ideal system to study using muons.  Our results show that there is a large change in relaxation rate on entering the superconducting state, pointing to a relatively low penetration depth, making these measurements ideally suited to ISIS where we can, in addition, take advantage of the high data rate.
DOI: 10.5286/isis.e.rb1720070
title: Structure of myoglobin-sugar-water systems

description: This proposal is a continuation of our previous experiment on NIMROD (Rb 1520094), where we studied aqueous solutions of trehalose (33 wt% trehalose) as well as myoglobin in the same solution (25 wt% myoglobin). The results of these previous measurements are very interesting and show that water and trehalose are homogenously distributed with plenty of hydorogen bonding inbetween. For the tenary system it is evident that myoglobin is prefentially surrounded by wate and that trehalose in the remaining solution causes a remarkable structural ordering of the myoglobin molecules. The aim of this proposal is both to elucidate whether the results are unique for trehalose, or will be similar for another sugar, and to determine how the ordering of the myoglobin molecules, as well as the distibution of the sugar molecules, are affected by a lower protein concentration and/or another sugar.
DOI: 10.5286/isis.e.rb1720217
title: Magnetic excitations in kagome antiferromagnet Mn3Ge

description: The Mn3Ge compound have recently attracted giant attention due to discovery of large anomalous Hall effect. This effect is believed to originate in the non-collinear antiferromagnetic structure of the compound. In the proposed experiment we intend to determine the energy landscape of the magnetic subsystem by means of thermal neutron TOF spectroscopy.