cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1520159
title: Magnetic ordering in AgFBF4  a nearly perfect 1D AFM with huge intra-chain coupling

description: One-dimensonal Heisenberg antiferromagnet is the only solid-state system, for which the precise analytical description has been derived; it orders magnetically at 0 K. Here we propose to study AgFBF4, which consists one-dimensional AgF+ chains, and which - according to the previous experiments as well as rigorous theoretical calculations - should exhibit the following unusual characteristics:1. the intra-chain magnetic interactions should be the strongest ever measuredand simultaneously2. the anisotropy of magnetic interactions should be the largest ever observed, rendering this system a model 1D material.The purpose of this project is to determine the value of the Neel point as well as of the order parameter of AgFBF4; according to our previous measurements at ISIS the Neel point must be lower than 0.3 K.
DOI: 10.5286/isis.e.rb1620191
title: Strain control of multiferroic domains:  towards solving the problem of polarisation fatigue in BiFeO3 thin films

description: We propose a neutron diffraction experiment to investigate substrate control of multiferroic domains in (111)-oriented BiFeO3 films. This is a continuation of a series experiments in which we have shown, contrary to previous reports, that the as-grown structure of (111)-BFO films not a rhombohedral monodomain but in fact consists of a sub-micron texture of monoclinic magneto-structural domains. The presence of these domains results in undesirable effects of polarisation fatigue and electrical breakdown. It has been shown the domain structure in BFO films depends dramatically on mismatch strain, so by measuring films grown on substrates with an order-of-magnitude lower epitaxial strain and with a substrate miscut, we aim to control the properties and populations of the multiferroic domains with the goal of growing a single magnetic and structural monodomain.
DOI: 10.5286/isis.e.rb1700043
title: Identifying interstitial oxide in a new melilite compound

description: We have recently developed a computational method to accelerate inorganic materials discovery by identifying compositions that are likely to yield new compounds. To demonstrate the method, we have identified a small region of the Sr-Y-Ca-Ga-O phase field and discovered two new compounds with two new structures within it. This work is currently in revision at Nature. As a response to initial reviews, we have successfully modified one of our new compounds (a structural derivative of melilite) to enhance its oxide ion conductivity, in an attempt to demonstrate that our route may lead to new functional materials. We wish to collect neutron powder diffraction on the modified melilite to identify the interstitial oxide ions that provide the ionic conductivity, and hence underpin our physical observations with structural understanding, to form a key part of the revised manuscript.
DOI: 10.5286/isis.e.rb1710049
title: The solution structure of E.coli peripheral membrane protein FtsA solubilised within a polymer stabilised nanodisc

description: We will measure the solution structure of a protein complex from bacteria essential for cell division. The two proteins, FtsA and FtsZ, are known to interact with each other with FtsZ forming a constricting ring, and FtsA being a membrane protein anchoring this ring to the membrane. Furthermore, we have prepared these proteins in a novel way using SMALPs: discoidal structures solubilising membrane proteins within a native lipid environment without the use of detergents which are a poor substitute for the natural lipid bilayer. While interactions are known, the structural details of the assembly are unknown. We propose to use small angle neutron scattering on SANS2D to measure the solution structure of this complex isolated in the most native-like state by using SMALPs, which is essential for the development of novel antibiotics and understanding the mechanism of bacterial cell division.
DOI: 10.5286/isis.e.rb1710317
title: Residual Stress Measurement by Neutron Diffraction on Aluminium Matrix Composite Joints Welded by Friction Stir Welding

description: Aluminium Matrix Composite (AMC) material systems offer unique combination of material and mechanical properties as compared to conventional monolithic materials with considerable industrial application potentials. Friction stir welding (FSW) may be developed as a viable route for joining AMC materials. As a solid state thermo-mechanical joining technique, FSW process would introduce considerable amount of residual stresses in joints. The residual stresses could have a significant effect on post-weld mechanical and particularly fatigue properties. The aim of this project is to measure residual stresses in AMC joints welded under different FSW conditions, which would enable the validation of residual stresses predicted by the computational models and develop optimum FSW process conditions and operational windows for sound AMC joints.
DOI: 10.5286/isis.e.rb1710448
title: New Metastable structures of ice from gas hydrates

description: Ice (the crystalline form of the water molecule) is one of the most structurally versatile systems known with at least 16 reported crystal structures. This proposal is for beam time to search for further structures made by the recovery of high-pressure gas hydrates to ambient pressure.
DOI: 10.5286/isis.e.rb1720054
title: Jahn-Tellar distortions in uranium compounds

description: A full understanding of the chemistry of the actinides has not been established, especially in comparison to transition metals. The treatment of nuclear waste by long term storage or partition & transmutation - the separation of actinides from lanthanides and subsequent exposure to high neutron flux - require a deeper understanding than we currently have. The key objective of this proposal is to structurally characterise a uranium and thorium compound using neutrons. Conventional X-ray diffraction is not an ideal technique as the uranium dominates, but with neutrons we can observe the coordinating atoms and we are looking for structural distortions at low temperatures to explain spectroscopic data (e.g. inelastic neutron scatting and variable temperature magnetism) we have collected. Moreover, there are few examples of uranium compounds characterised by this technique.
DOI: 10.5286/isis.e.rb1720086
title: Structural evolution of self-assembled cyclic-peptide hydrogels

description: Cyclic peptides which can self-assemble into long nanotubes provide unique properties which can be tailored for a diverse range of biomedical applications. Recently, we have demonstrated these peptides can further self-assemble to form a hydrogel under ambient conditions.  Hydrogels are very important systems in the biomedical industry as they provide unique properties allowing a wide-range in applications varying form wound care to a scaffold for cell culture. We have characterized these systems using several different techniques, but require the use of SANS to understand the fundamental processes governing their self-assembly, and testing how they behave under different biological conditions. By using this information we can design bespoke peptides, with highly tuned properties ideal for a broad and diverse range of applications.
DOI: 10.5286/isis.e.rb1720131
title: Insight into 4-hydroxyacetophenone polymorphs from single crystal neutron diffraction measurements

description: Beside the lattice energy, vibrational entropy has an important contribution to polymorph stability. We have developed a new method (NoMoRe - Normal Mode Refinement), which allows estimating vibrational entropy from frequencies, which are obtained from calculations and refined against single crystal diffraction data. We decided to apply NoMoRe to polymorphs of 4-hydroxyacetophenone (HAP). We would like to conduct multi temperature single crystal neutron diffraction measurements on for both polymorphic forms of HAP and conduct normal mode refinements and from obtained frequencies compute vibrational entropy. Additionally in X-ray diffraction pattern for form II, at 100K we found small additional peaks in one direction. Appearance of those small satellite peaks is related to methyl group behavior. Neutrons will enable us to locate hydrogen atom positions and ADPs for methyl group of HAP.
DOI: 10.5286/isis.e.rb1800101
title: ChipIR commercial access: ARISTA #2

description: Arista Networks June (2nd of 2018) commercial access to ChipIr beamline.
DOI: 10.5286/isis.e.rb1810203
title: Self-assembly of lipid and triblock copolymer-based amphiphiles for drug delivery

description: Soft self-assembled structures have been extensively used as drug nanocarriers. Their building blocks, naturally occurring and synthetic amphiphiles (lipids or block copolymers), have been proven to offer a wide range of morphologies on the nanometre scale. Careful design of the amphiphiles molecular structure and composition allows for self-assembly or structural transition of such nanoconstructs upon external stimuli. Here, we propose a study to characterize the effect of composition and temperature on the self-assembly behaviour of phospholipids and temperature-responsive triblock copolymers. Besides answering fundamental questions on the structure morphology of such nanoconstructs, the results of this study will be particularly important for the design of novel drug nanocarriers with tunable morphology and versatile applicability over a wide range of projects within our group.
DOI: 10.5286/isis.e.rb1810419
title: STRUCTURAL DYNAMICS IN MgCl2-BASED ZIEGLER-NATTA CATALYSTS

description: The proposal aims at revisiting the properties of disordered, nano-sized and structurally dynamic delta-MgCl2 particles as fundamental components of Ziegler-Natta (ZN) catalysts for olefin polymerization. Inelastic Neutron Scattering (INS) technique, coupled with advanced theoretical calculations, is expected to provide information on the atomic dynamics of MgCl2-based catalysts, in strong synergy with what obtainable from Raman and IR spectroscopies at UniTO. The proposal, motivated by a strong industrial interest within the DPI 2.0 programme (industrial funding partners: Borealis, Braskem, ExxonMobil, Reliance, SABIC, SCG Chemicals and Sinopec) and written in close synergy with our Japanese partners (T. Taniikes group, JAIST), stands up as a pioneering INS investigation on MgCl2 systems and as such may have a very high potential impact in the scientific community.
DOI: 10.5286/isis.e.rb1810860
title: Free volume calibration of Polystyrene (PS) bulk above and below its glass transition temperature

description: Free volume theory has successfully predicted and described all of the liquid-to-solid transitions in hard sphere system. However, in polymer system, the exact molecular picture of what is "free volume" is still vague. The only experimental observation which may be related to the molecular packing density and possibly the "free volume" is the small change in the scattering function, S(q) (or the pair correlation function), at q-1 in the range of monomer dimension. We propose to use NIMROD and inverse molecular dynamics Simulation to study the free volume in polystyrene (PS) bulk above and below its glass transition temperature to reveal the existence of free volume. As a direct quantitative evidence of free volume in polymer bulk, it can give more insight into the nature of glass transition.
DOI: 10.5286/isis.e.rb1810871
title: Study of superconductivity in Sc5Ir4Si10, Sc5Rh4Si10 and Sc5Co4Si10 using muon spin relaxation and rotation

description: Ternary compounds R5T4X10 crystallizing in primitive tetragonal structure (space group P4/mbm) present interesting physical properties. Of particular interests are the superconducting members of this series of compounds which include Sc5Ir4Si10, Sc5Rh4Si10 and Sc5Co4Si10. They exhibit superconductivity with Tc  8.6 K, 8.5 K and 4.9 K, respectively for Sc5Ir4Si10, Sc5Rh4Si10 and Sc5Co4Si10.  Superconductivity in these compounds have recently been revisited for possible multiband (two-gap) superconductivity. Therefore it would be of interest to further investigate the superconducting properties of Sc5Ir4Si10, Sc5Rh4Si10 and Sc5Co4Si10 using muon spin relaxation and rotation (µSR) technique to explore the nature of the superconducting gap and time reversal symmetry state. We therefore propose to carry out µSR study on these compounds using the MUSR spectrometer.
DOI: 10.5286/isis.e.rb1870002
title: New 3d heavy fermion behavior accompanied by a Lifshits magnetic liquid phase in a non-centrosymmetric compound Mn3CoSi

description: Recently, new phase with Lifshits invariant of incommensurability is reported as a solitonic spin-liquid state above the magnetically ordered phase on Fe1-yTe. It cannot be expressed by Gintzburg-Landau phase transition theory due to the Lifshits invariant. The term can be expected in a material with incommensurability or chiral magnet with Dzyaloshinskii-Moriya (DM) interaction. Recently, we have found heavy fermion behavior of a partial magnetic liquid phase in Mn3CoSi, which may be attributed to the Lifshits invariant due to the non-centrosymmetry. Wed like to reveal the heavy fermion with partial magnetic liquid state by muSR.
DOI: 10.5286/isis.e.rb1620482
title: Magnetic excitation spectrum near incipient SDW order in Nb1-xFe2+x
DOI: 10.5286/isis.e.rb1710097
title: Investigation of charge transfer in P3HT:PCBM under the condition of photoexcitation

description: Alternative energy sources such as solar cells demand is rapidly increasing due to the limited amount of fossil fuels that exist and the rising amount of CO2 in the environment. Organic solar cells have a low efficiency (~10%), but are cheap to produce. They consist of a blend of organic materials such as polythiothene (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM). They work by electrons in the P3HT HOMO level absorbing a photon, so that it jumps to the LUMO level, these electrons then move across to the PCBM LUMO level. This is known as charge transfer. In this experiment, we intend to probe the charge transfer in P3HT:PCBM using muons. The experiment will involve measuring the ALCs of P3HT and PCBM for light on and light off conditions and comparing the results.
DOI: 10.5286/isis.e.rb1710186
title: MuSR study on the hidden order in Irridates

description: Recently the 5d transition metal oxide Sr2IrO4 has attracted much attention due to its close analogy with high-Tc cuprates. A hidden broken symmetry phase, which is similar to the pseudo gap phase in cuprates, was found by second harmonic generation experiments. It was suggested that its properties bear the symmetries of a magneto-electric loop-current order. We propose to study this interesting phase by performing zero and longitudinal field muon spin relaxation experiments.
DOI: 10.5286/isis.e.rb1710335
title: Magnetic structure of a new quantum magnet

description: SrCuTe2O6 is a quantum magnet featuring spin-1/2 magnetic ions that are coupled intoantiferromagnetic chains with frustrated interchain coupling. An ideal spin-1/2antiferromagnetic chain is expected to have a spin liquid ground state with no long-rangemagnetic order and spinon excitations. However, the addition of interchain coupling that isfrustrated could lead to incommensurate long-range order that reflects the underlying physicsarising from the frustration. We wish to understand the magnetic structure corresponding to this long-range order in SrCuTe2O6 and explore different phases of the magnetic phasediagram by performing neutron diffraction on the WISH diffractometer.
DOI: 10.5286/isis.e.rb1710398
title: Distribution of Residual Stresses in 17-4PH Stainless Steel Pipe Due to Flow Forming Parameters

description: Flow forming is a well-developed metal forming process to produce cylinders, flanged components, shafts and gears etc. In flow forming process a hallow metal blank, a disc or a tube is mounted on a rotating mandrel and material is made to flow axially along the rotating mandrel by one or more rollers. This technique has increased the flexibility of incremental forming technology and an alternative technique to conventional forging. Due to the rapid mechanical deformation of the sample during flow forming, develops significant levels of residual stresses, which can lead to failure of sample during manufacturing. The knowledge of residual stress distribution in manufactured components will provide an acumen in understanding the impact of manufacturing parameters. One of the objectives of this project is to understand the impact of forming parameters in distribution of residual stress.
DOI: 10.5286/isis.e.rb1720488
title: DNA unwinding mechanism of the archaeal helicase PabMCM in its octameric configuration

description: The process of cell division requires precise duplication of the genetic material. The separation of the two strands of DNA and the progression of the replisome are driven by replicative helicases called Mini-chromosome maintenance (MCM) proteins. MCMs unwind genomic dsDNA to expose ssDNA template during the S-phase of the cell cycle. We have recently solved the first full-length octameric structure of the Pyrococcus abyssi MCM (PabMCM) by electron microscopy and SAXS. PabMCM can be found as single or double octameric ring assemblies in absence of DNA; however, bound to dsDNA, PabMCM is found exclusively in single ring assemblies bound to the DNA substrate. We now plan to use small angle neutron scattering to solve the structure of MCM/DNA complexes with contrast matching experiments. These are unique experiments that allow to discriminate the protein and DNA component in a full complex.
DOI: 10.5286/isis.e.rb1768003
title: Investigation of interface magnetic structure of Gd/Co multilayer

description: Rare Earths (REs) - Transition Metals (TMs) multilayers have a great importance in modern magnetism because of their unique properties due to their 4f orbitals: perpendicular magnetic anisotropy , antiferromagnetic (AF) exchange-coupling  and frozen frustrated magnetic state. Due to the interface-driven nature of RE/TM systems it is difficult to measure the exact magnetic structures of the individual layers using macroscopic magnetometry (SQUID) techniques. Additionally, at low temperatures the magnetisation of a RE layer in a RE/TM bilayer will be far larger than that of the TM layer, meaning it can be extremely difficult to deconvolute the two signals.  Here we propose to investigate the magnetic structure across interfaces of Co/Gd multilayer using PNR, which has its inherent properties to probe interfaces with high depth resolution.
DOI: 10.5286/isis.e.rb1800098
title: Determination of precipitation spacing in Cu-Cr-Zr alloys for fusion applications

description: Using small angle neutron scattering, we want to obtain representative measurements of the precipitate spacing in Cu-Cr-Zr alloys with known thermal history, over larger areas than typically probed - millimeters as opposed to hundreds of nanometers. This will allow us to infer microstructural and mechanical properties of larger assemblies containing Cu-Cr-Zr that have undergone more complex heat treatments or have been exposed to service conditions.
DOI: 10.5286/isis.e.rb1810010
title: FINDING NEW CLUES ON ARCHAEOLOGICAL BONES  HEAT-INDUCED CHANGES PROBED BY NEUTRONS

description: Human skeletal remains from archaeological settings are studied by neutron vibrational spectroscopy as an innovative way of analysing these kind of samples, particularly aiming at the assessment of heat-induced alterations. This work builds on the success of previous experiments at ISIS on human bones burned under controlled conditions, which allowed us to probe burning-elicited changes through specific spectral biomarkers, and constitute the first studies on human skeletal remains by neutron techniques [1]. The INS results obtained from the archaeological specimens (coupled to FTIR and Raman data) are expected to yield relevant bioarchaeological information, by correlating the spectroscopically detected structural changes due to burning to the temperature and duration of the burning event as well as to bone´s macroscopic characteristics (e.g. dimensions and colour).
DOI: 10.5286/isis.e.rb1810031
title: Understanding the interaction between antimicrobial peptide-loaded lipid particles with bacteria mimicking membranes

description: The number of antibiotic-resistant bacteria is increasing worldwide, and the demand for novel antimicrobials is constantly growing. Antimicrobial peptides (AMPs) could be an important part of future treatment strategies of various bacterial infection diseases. However, AMPs have relatively low stability, because of proteolytic degradation. As a consequence, carrier systems protecting the AMPs are greatly needed, to achieve efficient treatments. Dispersions of lipid-based liquid crystalline nanoparticles (cubosomes) are biocompatible drug delivery vehicles, well suited for delivery and protection of AMPs, due to their ability to encapsulate amphipathic molecules. However, the bacterial membrane disruptive properties of the AMP-loaded cubosomes remains unclear, but can be studied using neutron reflectivity.
DOI: 10.5286/isis.e.rb1810332
title: Cation-Exchanged Dion-Jacobson and Ruddlesden-Popper Phases

description: Multiferroic materials - those which exhibit spontaneous and switchable electrical and magnetic polarizations - have a wide range of applications. However preparing new magnetoelectric materials is challenging because ferroelectric and ferromagnetic properties are contraindicated. We have been working of a strategy of introducing magnetic behaviour to existing ferroelectric materials via topochemical cation exchange. Specifically, we are exploring the cation exchange chemistry of polar Dion-Jacobson and Ruddlesden-Popper phases to see if we can induce ferromagnetic behaviour whilst retaining the existing ferroelectric behaviour. We propose to collect high resolution neutron powder diffraction data from these exchanged phases, so we can determine their complex structural distortions, and thus determine if they retain their ferroelectric behaviour on cation exchange.
DOI: 10.5286/isis.e.rb1810845
title: Synthetic Ion Channels Formed By Self-Assembly of Crown Ethers

description: Ion channels are present in cell membranes and permit the transport of ions across from the cell interior to the cell exterior (or vice versa), and hence allow chemical and electrical communication between the two. Because of their importance, effort has been placed on the search for synthetic ion channels with which laboratory experiments can be conducted and closely controlled, in order to learn more about this critical phenomenon outside of the human body.Molecular self-assembly can provide a route towards ion channels in solution - specially-designed molecules that preferentially interact with each other rather than the solvent in which they are immersed, and form aggregates and superstructures. One such type of molecule is considered in this work, with a view to understanding more fully the interactions and aggregates formed in solution, which are to date poorly described.
DOI: 10.5286/isis.e.rb1810863
title: Internal structure of chitosan and modified chitosan nanoparticles for transmucosal drug delivery

description: Mucus is a viscoelastic gel present on various moist surfaces of human body including gastrointestinal tract, eyes, respiratory system, bladder and vagina. Administration of drugs via mucosal membranes offers a number of advantages as it can be used as an alternative to injections and sometimes gives an opportunity to deliver medication directly to the target organ. However, the mucus gel often acts as a barrier for successful drug delivery; it can trap drug molecules before they are able to reach surface cells and achieve therapeutic effects. The aim of our research is to develop nanoparticles capable of crossing mucosal membranes efficiently. We will use neutron scattering to probe the structure of these nanoparticles to understand how their structural features could affect their diffusivity through mucosal membranes.