cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1710356
title: Probing the local magnetic structure and magnetic ground states in strongly spin-orbit coupled Iridates

description: Strong spin-orbit coupling (SOC) has often lead to exotic properties in otherwise banal pool of 'paramagnetic' heavy ion oxides. In this context d4 Ir systems are exciting because for a 5d4 system a J=0 total angular momentum ground state should be realised in a jj coupling scheme, which has not been realized till today. This is due to the presence of a complex interplay and a subtle balance between interelectronic repulsion, correlation, crystal field and SOC, which makes the J=0 state a fragile one. In our last muSR  beamtime  at ISIS we could successfully probe the magnetic ground state of Ba2YIrO6 down to 60 mK which should help to close the actual controversy on this compound. However, situations with other systems Ba3MgIr2O9, Sr2LuIrO6 and Sr3LiIrO6 are still not understood and require detailed muSR studies down to milli-Kelvin temperatures
DOI: 10.5286/isis.e.rb1710360
title: Investigation of the magnetic hidden order in Sr2Ir(1-x)RhxO4 iridate with muon spin relaxation

description: In the 5d layered perovskite material, Sr2IrO4, spin orbit coupling and strong electron correlations combine to give rise to a spin-orbit coupled Mott insulator, with a pseudo-spin J=1/2 antiferromagnetic ground state. Recently, optical second-harmonic generation  measurements and polarized neutron diffraction in Rh doped Sr2IrO4 have highlighted an odd-parity hidden order developing prior to its antiferromagnetic state. This state possesses the same symmetries of a loop-current order, theoretically proposed to account for the pseudo-gap physics of superconducting cuprates. The aim of this proposal is to detect the tiny orbital moments associated with these current loops using the exquisite sensitivity of muSR in order to unravel the nature of the hidden order in these iridate materials.
DOI: 10.5286/isis.e.rb1710454
title: The structural role of carbonate groups in glass

description: We request GEM beamtime to study the structure of samples of sodium silicate glass with and without CO3 carbonate groups. The presence of CO3 carbonate groups in the glasses is a challenge to standard ideas about glass structure, because of the large valence of C-O bonds. By determining the environment of the CO3 groups we may be able to explain why CO2 cannot be dissolved in glasses below a certain modifier content (56 mol% Na2O for sodium silicate glasses), and yet beyond this composition the additional CO2 seems to be almost completely retained. It is unlikely that there are CO2 molecules trapped in the glass, but if they are there then the neutron diffraction results will have a good sensitivity to their presence. Dissolved CO2 in silicates (either as CO3 groups or CO2 molecules) is of particular geological interest.
DOI: 10.5286/isis.e.rb1500023
title: Testing through to data analysis
DOI: 10.5286/isis.e.rb1510022
title: Surface properties of biogenic polyaminesurfactant mixtures

description: Polyions and biogenic polyamine are ubiquitous in many important biochemical functions. We propose here to use neutron reflectivity to investigate their potential to induce and manipulate surfactant adsorption at the air-water interface and to promote surface multilayer formation. The measurements will explore a wider range of biogenic amine structures and build upon the significant insights obtained for the biogenic amines, putrescene, spermidine, and spermine, recently studied. The work is supported by a Leverhulme Trust Grant, (EM-2013-017, and has potential for widespread applications and in a greater understanding their biological role.
DOI: 10.5286/isis.e.rb1510053
title: DRUG EFFECTS ON INTRACELLULAR WATER: CISPLATIN IN HUMAN CANCER CELLS

description: Within a biological system such as a cell or tissue, water structure and dynamics are known to be changed by the presence of biomolecules or extrinsic entities (e.g. drugs), while in turn water is prone to disturb the conformational behaviour and function of biomolecules. Disruption of the coherent structure of cellular water by even very subtle stimuli is expected to have a significant cost at the functional level, and may even induce pathology.The present study aims at extending this concept to the activity of pharmacological agents. The INS technique will be used to probe the effect of an anticancer drug (cisplatin) on intracellular water structure in human cancer cells.This is an innovative way of tackling the drug´s pharmacodynamics leading to an improved understanding of its in vivo mode of action.
DOI: 10.5286/isis.e.rb1510084
title: Co-adsorption and competitive adsorption of eggshell membrane polypeptide against surfactant at the oil-water interface  NR study

description: In this work we explore how to use neutron reflection to study the interfacial adsorption from a natural eggshell membrane polypeptide at the oil/water interface. We will then proceed to study how premixed peptide and SDS adsorbed, followed by adsorbing peptide first and then replacing it by progressively adding SDS. The same expt will then be done in the reverse order to check how pre-adsorbed SDS is replaced by the peptide. We expect the ranges of replacing concentrations are different and these differences may well explain the different emulsion stability as often observed in product formulations. Neutron reflection is about the only method that could unravel such fantastic information about molecular adsorption and replacement at the oil-water interface. As the technique is pioneered on Inter and the signals are mostly weak, we request 4 days on Inter.
DOI: 10.5286/isis.e.rb1510088
title: Muon soft error effects at 16-nm FinFET technology nodes

description: Semiconductor industry is currently offering 16 nm technology node with FinFET fabrication processes. Soft error causing mechanisms and error rates for FinFET technologies are expected to be vastly different from those for planar technologies. This proposal is for the investigation of muon-induced soft errors for 16 nm SRAM and flip-flop (FF) designs. We will be using standard SRAM designs and a custom test IC containing multiple hardened and non-hardened FF designs. Since soft errors caused by muons may be significantly higher than that observed for prior technologies, tests are needed to understand their effects and failure rates to allow for development of predictive models. Results from these experiments will be supported with radiation transport simulations and circuit simulations. Results will support a dissertation and will be disseminated through publications.
DOI: 10.5286/isis.e.rb1510109
title: Magnetic Ordering in the Heavy Fermion CePtZn

description: In rare-earth containing metals, there is a strong competition between the tendency of these systems to magnetically order or form a superconducting state, mirroring in many ways the behavior of high-temperature superconductors that are of great technological importance today. In this work we will use muon spin relaxation techniques to study the onset of magnetic order at low temperatures in a new family of these compounds. Through this work we hope to gain a better understanding of the complex many-body interactions which govern the macroscopic properties of these materials, and in doing so, develop parallels which may help us explain exotic phenomena in a variety of materials systems.
DOI: 10.5286/isis.e.rb1510244
title: Investigation of excitonic physics in polycyclic aromatic hydrocarbon molecules

description: The MuSES project currently ongoing in the HiFi spectrometer gives unique opportunity in the field of photochemistry and photophysics of organic molecules. After two successful experiments on somewhat complicated molecules, we would now like to concentrate our efforts on understanding how singlet and triplet excitons affect Mu in a series of fused benzene ring compounds, which are smaller and less complex molecules, making the quantum-chemical calculations significantly easier.
DOI: 10.5286/isis.e.rb1510248
title: Detection of Spin-Polarized Conduction Electrons in Si by MuSR

description: One of the challenges of developing Silicon-based spintronics technology is developing non-destructive methods for characterizing spin-polarized conduction electrons. Si is indirect bandgap and optical magneto-optical methods don't work. We have demonstrated that laser-injected spin-polarized electrons enhance the spin-relaxation of bound Mu- in GaAs. The goal of the proposed experiment is to demonstrate the ability of MuSR to detect spin-polarized electrons in Si and an indirect bandgap semiconductor for the first time, thus opening the possibility for MuSR to contribute uniquely to semiconductor spintronics research.  A 10 ns duration UV pump pulse tuned to the spin-polarization resonance will inject spin-polarized electrons in bulk Si and the HI Field muon spectrometer field-tuned to the avoided level crossing resonance of various Mu species in Si will probe laser-induced changes.
DOI: 10.5286/isis.e.rb1510340
title: Dynamics and Phase Transitions in Catanionic Vesicles

description: The catanionic vesicles are unilamellar or multilamellar spheroid structure composed of cationic and anionic surfactant molecules assembled into bilayers. Vesicles forms by sodium dodecyl sulfate (SDS), and cetyltrimethylammonium bromide (CTAB), can form complexes with biopolymers and enter the cells via membrane. This type of vesicles undergoes a transition from multi to a unilamellar phase (MLV - ULV) at high temperature.  Preliminary QENS study and differential scanning calorimetry indicated that there exists another transition related to solid gel to fluid transition, which may be responsible for the faster lateral motion in the thermally cycled sample. Aim of the proposal is to carry out a fixed window scan in heating and cooling cycle and QENS measurement at and around the transition temperatures, enabling us to correlate with the different dynamical motions.
DOI: 10.5286/isis.e.rb1510409
title: A Structural Study of Alkaline-Earth Tellurite Glasses.

description: We wish to better understand the interaction between the alkaline earth modifiers and the tellurite glass network.  The aim is to relate structural changes in the glasses with the addition of modifier to the functional properties, such as Tg, density and optical properties.  To achieve this we propose to study a series of alkaline-earth modified tellurite glasses, x MO.(1-x) TeO2, where M= Mg, Ca and Ba and x = 5-35 mol.%, using neutron diffraction.  A combination of direct fitting, isostoichiometric differences and computational analysis will be used to determine the coordination numbers of tellurium, nTeO, and the alkaline earth modifiers, nmo.
DOI: 10.5286/isis.e.rb1510421
title: Inelastic neutron scattering on hydride perovskites MLiH3 and MLiD3 (M = Sr, Ba)

description: Recently, a new class of light emitting materials was discovered. When europium is doped into metal-hydrogen compounds, so-called metal hydrides, such materials emit bright yellow, green or red light when excited by UV radiation. At low temperatures the emission spectra of europium doped SrLiH3, BaLiH3 and the corresponding deuterides exhibit surprising features, which suggest coupling to vibrations of the lattice of the solid compounds. Inelastic neutron scattering experiments are being proposed, which will help to prove this coupling of the luminescence (emitted light) to lattice vibrations. This will help in the understanding of the origin of the light emission in this new class of luminescent materials and to tune the wavelengths for possible lighting application. Such inelastic scattering experiments can best be performed at the instrument TOSCA at ISIS.
DOI: 10.5286/isis.e.rb1510609
title: Investigation of synthetic georgeite by inelastic neutron scattering spectroscopy

description: Synthetic georgite has shown high catalytic activity for a number of catalytic processes including methanol synthesis and the water gas shift reaction. Consequently, it is of considerably interest to the catalysis community. However, characterization of this material is extremely difficult due to its highly amorphous nature. We propose to compare, on TOSCA, measurements of georgeite in its initial state and after heating to 100, 225 and 325°C (corresponding to steps in the TGA) to understand the importance of the occluded water within the structure. Then under the optimal conditions measure the spectrum of zincian georgeite. Additionally we would perform measurements on other reference hydroxycarbonates specifically: malachite, aurichalcite and rossersite. Based on an Xpress measurement of malachite an 8h measurement time per sample is required. Accordingly, we request 3 days on TOSCA.
DOI: 10.5286/isis.e.rb1520061
title: Sweet taste chemoreception unveiled. The case of lactose and sucrose.

description: In the late 1960s, a molecular theory of sweet taste was proposed, based on the presence of a ?functional structure? in all sweeteners, eliciting the sweet response via the interaction with a complementary tripartite site in the taste bud receptor. Remarkably, the role of water as a likely mediator, through hydrogen bonding, between the sugar and the receptor has been almost totally neglected. Looking at the hydration shells of carbohydrates like cellobiose (tasteless), glucose (sweet), and trehalose (moderately sweet), we have observed that water molecules are H-bonded to specific sites of cellobiose and glucose, while almost no H-bonding has been observed between water and trehalose. We wish to look at the hydration shells of two sugars, lactose and sucrose, to seek for an explanation, at the atomic length scale, of the sweet taste chemoreception.
DOI: 10.5286/isis.e.rb1520124
title: The structure of particle stabilised foams

description: Many formulated products pass through or end up as foams, comprising immiscible millimeter sized bubbles dispersed into an aqueous continuous phase. Frequently, surfactants or polymers are employed to stabilize the foam structures. Recently, similarities between the role of small solid particles in stabilizing aqueous foams and conventional surfactants in air/water systems have been observed. Here, we wish to explore these facets, focusing on aqueous foams stabilized by silica particles of differing hydrophobicity. These silica foams can be remarkably stable (months), but with seemingly small changes in hydrophobicity, they can also show little or no foaming ability at all. Further, the non-foaming systems may be rendered substantially more foaming by the addition of simple salt. These observations suggest a complex and fascinating adsorption behaviour at the air-water interface.
DOI: 10.5286/isis.e.rb1520136
title: Multilayering of Methyl Ester Sulphonates at the Air-Aqueous Interface

description: Surfactants usually form a single layer of molecules at the surface of water. We have shown, surprisingly, that under certain conditions more than one layer may form. When this happens the system seems to become a powerful wetting agent (it will wet Teflon). A whole range of useful technological properties would follow from this, e.g. more effective detergency, and since the phenomenon seems to be associated with more charged ions such as calcium and aluminium, hard water would enhance detergency in contrast to the usual reduction. It is important to be able to extend this behaviour to more surfactants. There is also a drive to use renewable materials. The methyl ester sulphonates not only have the right features to exhibit multilayering but are from the renewable resource of palm oil.
DOI: 10.5286/isis.e.rb1520386
title: Vibrational dynamics and proton sites in proton conducting perovskites

description: Solid oxide fuel cells (SOFCs) operating at intermediate temperatures are a promising clean energy technology. At the heart of these devices is a proton conducting oxide electrolyte, but because of the difficulty in developing electrolytes with sufficiently high conductivity it has been difficult to develop, and commercialize, the technology.This proposal requests 6 days on MERLIN in order to measure the vibrational spectra of the four proton conducting perovskites BaCe0.9Y0.1O3H0.1, SrCe0.9Y0.1O3H0.1, BaZr0.9Sc0.1O3H0.1, and BaScO2(OH), with the aim to obtain information about the proton sites present. Such understanding is crucial for the systematic development of new proton conductors with better performance, i.e. higher proton conductivity, which in turn is critical to future breakthroughs in the development of SOFCs working at intermediate temperatures.
DOI: 10.5286/isis.e.rb1520436
title: Crystal Field Excitations and phonon density of state in Ferromagnetic Superconducting Sr0.5RE0.5FBiS2 (RE=Ce, Nd and Pr) using Inelast

description: Recently some of us studied the presence of superconductivity (SC) under hydrostatic pressure (0?2.5 GPa) in Sr0.5RE0.5FBiS2 with R = Ce, Pr, Nd, and Sm (crystallized in tetragonal P4/nmm space group).  At ambient pressure, though the RE = Ce (also La) exhibits the onset of SC below 2.7 K, the Nd, Pr, and Sm samples are not superconducting down to 2 K. Further RE=Ce and Sm show an onset of ferromagnetic transition below 8 K at ambient pressure.  With application of hydrostatic pressure (up to 2.5 GPa), superconducting transition temperature (Tc) is increased to around 10 K (at 1.5Gpa) for all the studied samples.   We propose here to investigate superconducting ground state of Sr0.5RE0.5FBiS2 through inelastic neutron scattering experiments to investigate the crystalline electric field (CEF) excitations of rare earth ion (RE3+=Ce, Pr and Nd) as well as phonon density of state.
DOI: 10.5286/isis.e.rb1610300
title: Crystal and magnetic structures of mixed-valent V2OPO4

description: The electronic states of transition metal oxides usually result from a coupling between the three degrees of freedom: charge, orbital and spin states. When metal-metal distances are short, direct bonding interactions between M ions having localised t2g orbital order can give rise to more complex quantum electronic states called orbital molecules [1]. They appear as cation site distortions coupled through their orbital ordering and sharing of electron density, and could have applications in orbitronics. Mixed valent transition metal oxides with face- or edge-shared octahedra are good candidates to display such phenomena. As part of an ERC grant, we are hunting for new examples of compounds with orbital molecules. A variable temperature neutron diffraction study is needed to determine the magnetic structure and to study the structural transition of V2OPO4.
DOI: 10.5286/isis.e.rb1610328
title: Structural and thermodynamic properties of EVOH (ethylene-vinyl alcohol) based microgels and their interaction with surfactants

description: Poly(vinyl alcohol) is a biocompatible water-soluble polymer of great interest thanks to its large-scale applications for production of drug-delivery systems, sensors or membranes with selective permittivity. We are currently studying a new route, which uses the salting-out effect (adding NaCl), for the preparation of PVA-based physical microgels. With the aim of extending the field of application of these systems, microgels made up of two PVA-based copolymers (EVOH), formed by ethylene and vinyl alcohol at different molar ratios, were prepared. Due to the lack of information about EVOH-based microgels in the literature, a SANS study would be fundamental to understand how different parameters, such as salt and surfactant concentration, affect the aggregation process and the thermodynamical properties of such microgel solutions.
DOI: 10.5286/isis.e.rb1610452
title: Force transfer mapping in cemented granular materials under applied boundary loads (II)

description: The mechanical behaviour of porous granular rocks is highly complex due to the fact that they exhibit a multiscale interaction of three different phases: grains, cement and pores. Recent experiments at ENGIN-X (RB1320418 and RB1510338) have proven that neutron diffraction scanning during in-situ loading tests can aid in the understanding of the (micro-)mechanisms that act during the deformation and eventually lead to failure of such materials. In the proposed experiment, which is a continuation of the aforementioned ones, a new version of a plane-strain loading device will be used (two previous prototype versions were used RB1320418 and RB1510338). The new device will enable Neutron Diffraction scanning in combination with Digital Image Correlation, allowing investigation of the different deformation mechanisms leading to failure in porous granular rocks and how cementation affects this.
DOI: 10.5286/isis.e.rb1620024
title: Magnetic frustration induced by applied magnetic fields in CeRhIn5

description: Quantum critical points (QCPs) have attracted continuous scientific interest due to the emergent phenomena observed in their vicinity, including unconventional superconductivity and quantum magnetism. Understanding quantum criticality is therefore of great interest, and heavy fermion materials are particularly useful in this regard. Recently local quantum criticality has been invoked theoretically, where the Fermi surface is the critical degree of freedom. CeRhIn5 is believed to be a candidate for a local QCP, but the issue remains controversial. Theory suggests a global phase diagram in which the type of QCP depends on the amount of frustration in the system. So far, however, there has been little effort to quantify the frustration in candidate materials. We propose to quantify the magnetic frustration in CeRhIn5 using inelastic neutron scattering.
DOI: 10.5286/isis.e.rb1620037
title: Exceptionally High Adsorption of Carbon Dioxide and Light Hydrocarbons in a Tetra-Amide Functionalised Metal-Organic Framework Material

description: Porous functional metal-organic framework (MOF) materials show great potential for high capacity gas storage and separation. We seek to develop new materials for carbon capture and hydrocarbon separation and request 4 days on WISH to study the preferred binding sites and locations of adsorbed gas (CO2, C2D2, C2D4 and C2D6) molecules within an amide-functionalised MOF showing record-high adsorption capacities of CO2 and light hydrocarbons. The high resolution, low background and large d-spacing capabilities of WISH make it ideal for analysing the precise locations of gas molecules (particularly for hydrocarbon molecules) within this porous MOF and to define the preferred orientations of molecules with respect to the binding sites (in this case amide groups) on the pore surface. This study will reveal key insights into the excellent storage capacity of CO2 and light hydrocarbons in this MO
DOI: 10.5286/isis.e.rb1620236
title: Superconductivity in the layered semimetal Bi3O2S3

description: Bi3O2S3 is a newly discovered superconductor with a critical temperature ~4.5 K and an upper critical field of 4.8 T. It is highly unusual among the new layered structures in containing neither Cu nor Fe, yet showing superconductivity in an undoped state, and having a bandstructure which is semimetallic with a very low carrier density. How this will influence the superfluid stiffness of the condensate is an intriguing question that muon-spin rotation is ideally suited to answer.