cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1710255
title: Engineered anisotropic liposomes for drug delivery

description: It is well established that the anisotropy of nanoparticles has a dominant effect on increasing their uptake by cells. However, the advantage of anisotropy for cell penetration has yet to be utilised for soft nanoparticles such as liposomes, which have wide-ranging applications in drug delivery and diagnostics. This is because their formulation is far from trivial.  Here we propose a study of the morphology of nanometre-scale anisotropic liposomes we have formed by adjusting both the osmotic balance and cholesterol content, which leads to a significant proportion of rod-shaped liposomes. To our knowledge, this is the first study of the effect of cholesterol and osmotic imbalance on the morphology of nanometre-sized unilamellar liposomes. Its findings will feed directly into several projects within our group and open the door to liposomal drug delivery vectors with tuneable anisotropy.
DOI: 10.5286/isis.e.rb1710502
title: Copy of: Neutron spectroscopy of a novel family of Ln2 dimers

description: Molecular nanomagnets containing 4f ions are attracting an increasing interest because of their large magnetic anisotropy and slow relaxation of magnetization originating from their unquenched orbital angular momentum. Clusters made of such ions are promising candidates for ehancing their slow relaxation of the magnetization at relatively high temperatures. Recently, an interesting family of asymmetric Ln2 dimers has been reported with sizable exchange interaction between the magnetic ions and large single ion anisotropies.  Here we propose to exploit the MARI and IRIS spectrometers to investigate the spin dynamics of two compounds of the series, Yb2 and Er2 dimers, to better understand the role of the exchange interaction and crystal field in the relaxation mechanism.
DOI: 10.5286/isis.e.rb1720004
title: A μSR study of non-centrosymmetric superconductor Zr3Ir

description: We propose to investigate the effects of the electron- phonon interaction on the time reversal
symmetry breaking phenomenon of non-cetrosymmetric superconductors. μSR is the ideal
tool to investigate such time reversal symmetry breaking type of phenomenon. We therefore
request 4 days on the MUSR spectrometer to extend our study.
DOI: 10.5286/isis.e.rb1720502
title: Investigating Superconductivity and charge density wave in 2H-PdxTaSe2

description: PdxTaSe2 series is an excellent system for the investigation of the interplay between CDW and superconductivity which shows quantum critical point for x = 0.1. Very recently, we have studied 6% and 12% Pd doping samples of PdxTaSe2. We detect spontaneous fields in the ZF-µSR data only for the 6% Pd doping sample, most probably associated with time-reversal-symmetry (TRS) breaking superconducting state. This probably suggests that the exotic superconducting state observed in the 6% Pd doping sample is due to its interplay with CDW phase. However, a firm conclusion can only be reached if we are able to do a systematic study of the full phase diagram of the PdxTaSe2 series. Here we propose to study 3%, 8%, 10% and 15% Pd doping samples of the PdxTaSe2 series using the MuSR instrument. We ask for 8 days of MuSR beamtime to complete this project.
DOI: 10.5286/isis.e.rb1768012
title: Crystal field and spin-wave excitations in the quasi-2D honeycomb zigzag antiferromagnet Na2Co2TeO6

description: The microscopic origin of the zigzag magnetic ground state in a honeycomb lattice of the quasi-2D antiferromagnet Na2Co2TeO6 is debatable. The zigzag phase may occur due to (i) the J1-J2-J3 Heisenberg models for a wide range of exchange parameters, (ii) hierarchy of exchange interactions between nearest neighbours due to orbital ordering, or (iii) presence of strongly anisotropic interactions in the proximity of the Kitaev spin liquid. We propose an inelastic neutron scattering measurements on Na2Co2TeO6 using the Merlin spectrometer  to determine the origin of the zigzag ground state (out of the above three possibilities) as well as to explore the possible signature of quantum effects
DOI: 10.5286/isis.e.rb1770000
title: muSR study of ferromagnetic fluctuations in heavily overdoped Bi-2201 cuprates

description: This proposal is to investigate ferromagnetic (FM) fluctuations recently suggested to reside in the heavily overdoped regime of hole-doped cuprate superconductors. From magnetization, transport and preliminary zero-field muSR results in Bi-2201, we have suggested that FM fluctuations might exist in the heavily overdoped regime. By investigation the hole concentration dependence of the muon-spin depolarization rate and the effect of the Fe substitution on the muon-spin depolarization rate in Bi-2201, the existence of FM fluctuations and their doping dependence in the heavily overdoped regime would be clarified, leading to the understanding of the relation between the superconductivity and ferromagnetism in the heavily overdoped regime of hole-doped cuprate superconductors.
DOI: 10.5286/isis.e.rb1800010
title: CsDSO4
DOI: 10.5286/isis.e.rb1510058
title: Low Temperature Structural Investigation of the Triangular Lattice Material TbInO3

description: The room temperature crystal structure of TbInO3 realises a geometrically frustrated two-dimensional triangular lattice of Tb3+ J = 6 cations. We have prepared ~ 6 g of high quality, single phase, polycrystalline TbInO3 and are currently involved in a study of its intriguing magnetic behaviour that arises as a result of its frustrated network of spins. We request one day on HRPD with a He cryostat in order to study the low temperature structure of TbInO3 at regular temperature intervals in the range of 1.5 ¿ 300 K. We will investigate whether any subtle lattice distortion occurs at low temperatures to which the magnetic properties of TbInO3 will be sensitive. The use of neutrons is required in order to refine the oxide anion positions within the structure so that we can model the crystal field environment around the Tb3+ cations in TbInO3.
DOI: 10.5286/isis.e.rb1510137
title: Magnetic ordering in AgFBF4  a nearly perfect 1D AFM with huge intra-chain coupling

description: We propose to investigate AgFBF4, a compound known for &gt; 20 years, with muon spectroscopy. The scope is to determine the 3D ordering temperature as well as estimate the value of J for this Ag(2+)-based 1D antiferromagnet, which shows the shortest Ag-F bond length ever measured (~ 2 Å). Our rigorous DFT calculations (both +U and hybrid HSE06) point to an unprecedented large absolute J of 331 meV, which is &gt;30% larger than that measured for Sr2CuO3. The J values are usually reproduced with satisfactory accuracy at this level of calculations, for example the value computed for Sr2CuO3 is -253 meV (= overestimated by &lt; 5%). If this is confirmed by experiment, fluoroargentates(II) would outperform isoelectronic oxocuprates(II) and rank second to none as far as the absolute value of J via one atom is considered. Moreover, AgFBF4 should be even closer to perfect 1D behaviour than Sr2CuO3.
DOI: 10.5286/isis.e.rb1510209
title: A µSR stoichiometry study of TixV1-x alloys  superconductivity in the presence of itinerant spin fluctuations

description: This is a continuation proposal, for work carried out previously on the EMU and MuSR spectrometers.  We have determined that spin fluctuations are present in this system, by directly measuring their fluctuation rate, and have also fully characterized the vortex lattice state for one particular stoichiometry.  We now need to determine how the spin fluctuation behaviour changes with the Vanadium content, as this will allow us to see the importance of the spin fluctuations in the superconductivity - are the phenomena intrinsically linked, or coincidentally present in the superconducting state?  The former exciting possibility sees this seemingly conventional system exhibiting an unconventional pairing mechanism, with Cooper pairs that are bound not via the electron-phonon interaction, but by fluctuating spins.  This would provide a link to the physics of the high-Tc cuprate superconductors.
DOI: 10.5286/isis.e.rb1510384
title: High-pressure studies of energetic co-crystals and salts

description: This proposal will explore the effects of elevated pressures and temperatures on the structures of an energetic co-crystal containing nitroguanidine (NQ)and  an energetic salt formed  containing nitrotriazolone (NTO).  Both NQ and NTO are used in explosive formulations and as propellants.  The wider project aim is understand the types of structures formed by energetic co-crystals/salts, and discover whether  these materials have enhanced properties, e.g. reduced sensitivity to accidental initiation, improved long-term storage and thermal stability. It is important to understand the responses of such materials  to elevated pressures and temperatures, on the basis that extreme conditions are experienced during detonation processes. High-pressure structures inform us about how energy may be transferred within the material, thereby guiding the design of safer explosives and propellants.
DOI: 10.5286/isis.e.rb1510527
title: Variable temperature structural study of oxides with low thermal conductivity

description: The aim of the experiment is to investigate the temperature evolution of the crystal structure for two transition metal oxides with low lattice thermal conductivities. This will focus on the evolution of the structure (e.g. bond distances and angles) but also target the dynamics of the lattice vibrations through analysis of the thermal displacement parameters.
DOI: 10.5286/isis.e.rb1510566
title: Intercalation Mechanisms and Crystal Chemical Lithium Environments in High-Rate Nb-based Energy Storage Materials

description: In this proposal, we seek to explore the crystal chemical environment of intercalated lithium in three related Nb-based oxide materials in order to resolve a mechanistic understanding of high-rate energy storage.  Three transition metal oxides, T-Nb2O5, H-Nb2O5, and Ti2Nb10O29, are model examples of high-rate layered, conventional shear, and high-rate shear structures.  Neutron diffraction of these compounds with various degrees of inserted lithium will clarify the relationship between the electrochemical properties and structural features.  It is our objective to interpret the structures at various points of lithiation to better understand the mechanism of high-rate energy storage; this is all toward the goal of realising high-capacity and high-power in a single device.
DOI: 10.5286/isis.e.rb1510567
title: High pressure phase transitions in metal-formate perovskites

description: The family of guanidinium metal formates has the perovskite structure and, like many perovskites, is of interest for these materials' magnetic and electric properties, in particular the possibility of multiferroicity. The phase diagrams of these compounds, however, remain largely unexplored. We have recently (RB1410586) collected PEARL data demonstrating that both the cobalt and the manganese compounds have high-pressure rhombohedral phases. Unfortunately, we lost substantial amounts of beam time both in the original experiment and in replacement time, and thus collected relatively little data on these new phases. We therefore propose to collect data at more pressure and temperature points to enable a full investigation of the structural changes associated with this phase transition, in particular the relative distortions of the coordination polyhedra and framework structure.
DOI: 10.5286/isis.e.rb1620010
title: In search for a new correlated quantum phase in the CDW 1T-TaS2

description: TaS2 is a quasi-2D metallic compound revealing strong electron-phonon coupling responsible for charge-density-wave (CDW) instabilities. The compound undergoes 3 CDW transitions; from incommensurate CDW phase to a nearly commensurate CDW phase at 350K and finally below 160K to commensurate phase. Nature of this phase is under intensive investigation. Twelve out of thirteen Ta4+ 5d-electrons form molecular orbitals in David star patterns, freeing 1 electron. It is not clear how these orphan spins behave at low temperatures. Our susceptibility data and preliminary µSR spectra measured at EMU beamline on high-quality TaS2 powder suggest that a short-range correlation might exist at low temperatures: because of time shortage during Xpress beamtime our data suffer from poor statistics. Therefore, we propose to measure weak local field in the CDW TaS2 phase by means of muon precession at EMU.
DOI: 10.5286/isis.e.rb1620033
title: Aggregation of random co-polymers

description: This proposal builds upon the successful study of a cationic copolymer capable of forming polymer micellar-like aggregates, simply by reducing pH (D33 at ILL 9-12-433 see report).  Moreover, the size of aggregates could be tuned by adjusting pH during polymerisation. The copolymer system is comprised of a small mol. % (5-17) N, N-dimethylaminoethyl methacrylate (DMAEMA) copolymerised with methyl methacylate (MMA). This type of copolymer is significant for offering a simplified and direct route to cationic aggregates, as compared with common block copolymers.  The proposal prompts a re-think of the general approach: can the careful design of random (surface-active) copolymers, offer similar control over aggregations, circumventing the need for harder to prepare block copolymers?
DOI: 10.5286/isis.e.rb1620121
title: Interaction of Lignosulphonates with model surfactant systems by Small Angle Neutron scattering

description: With the biobased economy growing substantially and pressure to reduce reliance on palm and crude oil derived materials, it is vital that the Home and Personal Care industry develops frameworks for deploying sustainably sourced alternative materials. Lignin is naturally abundant and integral part of the secondary structure of plant cell walls structure. It is often simply burned as a waste product. With such an abundance of this material it is beholding on responsible innovation to find applications for waste derived materials. Certain lignin derivatives are finding limited application in heavy industry and in crude oil recovery. Their properties are not well understood and this study is attempting to understand how they behave in an environment more close to Home and Personal care, in order to assess their future potential for deployment.
DOI: 10.5286/isis.e.rb1620138
title: Experimental compositions of NbCoSn and ZrNiSn based half-Heusler thermoelectrics

description: The aim of the experiment is to determine the experimental compositions of a number of half-Heusler intermetallic compounds. These are the Nb1-xZrxCoSn, NbCoSn1-zSnz and ZrNiMySn (M = Ni, Cu) series which show promising thermoelectric properties. Neutrons are essential due to the lack of X-ray scattering contrast between the elements present.
DOI: 10.5286/isis.e.rb1620177
title: Magnetic Excitation Spectrum of the Fe19 High Spin Molecular Nanomagnet

description: Our recent WISH study of the low temperature longe range ordered magnetic structure of the Fe19 single molecule magnetic system with S=35/2 produced an easy spin axis that is at variance with the conclusions of a previous EPR study and a mode of ordering that differs from intermolecular coupling via purely dipolar interaction.  The apparent difference in easy axis is believed to be the result of the EPR measurement mixing in a low lying S=33/2 excited state with a different easy axis from that of the ground state. The proposed inelastic neutron studies using LET will determine the excitation spectrum of the S=35/2 ground state and the S=33/2 excited state and follow the splitting of the spectrum as the system undergoes long range ordering below 1.2 K. These new measurements should help resolve the discrepancy and clarify the basis for interpreting the magnetic properties of this system.
DOI: 10.5286/isis.e.rb1620247
title: ORGAN PIPES NEUTRON IMAGING

description: A neutron radiography study will be conducted on tin- and lead-rich organ pipes fragments. We will try to infer, by energy selective neutron imaging too, whether different crystallographic phases (that is tin-alpha, tin-beta, cassiterite or romarchite) reflect the visible alterations patterns. We aim to demonstrate that energy selective neutron imaging can give relevant indications in future archaeometallurgy studies, extending the method also to real archaeological samples (not only fragments), where only non-destructive experiments can be performed (often even in the presence of patina or corrosion layers).
DOI: 10.5286/isis.e.rb1700029
title: Round Robin on TOF Texture Analysis: ENGIN-X

description: In view of advances in texture research at pulsed neutron sources, we propose that ISIS participates in a 'Texture Round Robin' to benchmark the existing texture analysis capabilities on time-of-flight instruments. The Texture Round Robin will enable ISIS to check where it stands with respect to conventional neutron texture analysis and with respect to other TOF instruments. The Round Robin will identify strengths and shortcomings of texture analysis on GEM. By working together with instrument scientists at other facilities, this will eventually help identifying ways to improve the data reduction and data analysis routines. We require 2 days of beamtime on GEM for taking data on 17 round robin samples. We also ask for 2 days on ENGIN-X to run five of the round robin samples for an ISIS-internal comparison of extracted ODFs.
DOI: 10.5286/isis.e.rb1710057
title: Local Atomic Structure of High-Entropy Alloys

description: High Entropy Alloys (HEAs) are loosely defined as solid solution alloys that contain more than five principal elements in equal or near equal atomic percentage. The concept of high entropy introduces a new path of developing advanced materials with unique properties, which cannot be achieved by the conventional micro-alloying approach based on only one dominant element. In contrast, HEAs have a number of constituent elements in nearly equal portions and the increased disorder consequently stabilizes a single phase solid solution. Neutron diffraction is the first choice for getting detailed structural information on HEA samples. However, due to the high number of contributing elements, it is difficult to derive adequate structural data from a single diffraction experiment. Due to the above difficulties, neutron Compton scattering is the local dynamics  probe of choice.
DOI: 10.5286/isis.e.rb1710141
title: Study of the reorganization of DES upon dilution with Benzylalcohol

description: Nanoporous carbons are of great importance for development of energy storage and gas adsorption devices. The critical parameter is pore size and it is difficult to predict. Our group is focused on preparing such carbons from solvents that contains a carbon precursor and does not contain water, the so called deep eutectic solvents (DES). Normally, DES are mixed with water to generate pores however, sometimes water cannot be used in the preparation of materials. In previous experiments we hypothesized that pores come from the formation of DES-solvent nanodomains. Some techniques like H NMR and Brillouin spectroscopy reveals that DES-solvent domains  change their tendency at different dilutions depending on the solvent. In this experiment we want to analyse DESs diluted with benzyl alcohol using neutron diffraction to understand the differences found  when mixing a DES  with BA or W.
DOI: 10.5286/isis.e.rb1710144
title: Probing the magnetic structure of transition metal pyrovanadates M2V2O7  (M = Ni, Co, Mn).

description: Transition metal pyrovanadate M2V2O7 (M = Ni, Co, Mn) exist with a great variety of crystal structures, which are reflected in the richness of their physical properties. Magnetic ground states of these oxides depend strongly on the environment surrounding the transition metal and also on the exchange interaction pathways. It is expected to be quite interesting to observe the magnetic structure of Co2V2O7 below TC considering canted antiferromagnetic ground state as evident from magnetization data. The observed dielectric anomaly at TN and martensitic-like transition around room temperature in Mn2V2O7 and the multiple magnetic ordering in Ni2V2O7 provoke to study their magnetic structure. We therefore propose to carry out powder neutron diffraction studies on Mn2V2O7, Co2V2O7 and Ni2V2O7 samples to determine the magnetic structure as well as any structural anomalies occurring at TN or TC.
DOI: 10.5286/isis.e.rb1710174
title: Exploring Multiferroic Couplings in Ca2MnO4

description: The Ruddlesden-Popper (RP) compounds An+1BnO3n+1 exhibit a broad range of technologically interesting properties such as high-Tc superconductivity, colossal magnetoresistance, metal to insulator transitions and ferroelectric / multiferroic ground states. In a study of one of these compounds Ca3Mn2O7, we have recently validated key predictions regarding a novel kind of ferroelectric mechanism which has a strong coupling to magnetism.  We request now three days on PEARL to study the closely related phase Ca2MnO4 by high pressure Neutron powder diffraction, which has another intriguing property arising from the coupling between magnetism and strain.  Our result will allow us to ascertain how this multiferroic interaction is mediated and ultimately how it may be optimised in this and similar systems such that it may ultimately have commercial application in the renewable energy sector.
DOI: 10.5286/isis.e.rb1710418
title: Quantum magnetism in copper-oxalate networks ranging from isolated triangles through 1D chains to 2D layers

description: The oxalate ligand provides a flexible way of constructing metal organic framework systems based on metallic ions such as Cu and their structures can be finely tuned via careful choice of templating counter ions, leading to characteristic dimensionalities for the arrangement of magnetic ions ranging from isolated clusters (0D), through 1D chain systems to 2D layered networks.  The systems proposed to be studied here have shown no evidence of magnetic ordering or spin freezing down to 2 K although one is believed to have an antiferromagnetic transition at 1.6 K.  These systems therefore all merit further investigation at low temperature using muSR. The primary goal here will be to search for any transitions present in the 50 mK to 2 K region and the secondary aim will be to carry out spin dynamics studies via LF muSR to characterise the magnetic behaviour of the ground state in each case
DOI: 10.5286/isis.e.rb1710444
title: Resolving the manifold setting structure of protiated vs D2O portland cements

description: Models of cement have been formulated to further understanding. The dominant being Jennings layered colloid model. Therein, idealised silicate layers are interspersed with Ca-ions and H2O to form Ca-Si-Hydrate gel (C-S-H); comprising ~70% of the matrix and responsible for cohesion of the components and bulk mechanical properties. Jennings models have never been tested nor questioned. NMR work evidences a C-S-H distribution of Q0:Q1:Q2 as ~10:67:23. Hence, the majority of Si-atoms are terminal and bridging O-atoms in the minority, making layered and extended-silicate structures improbable. Entropy would agree.Our work on C-S-H gel showed layered structures to be the least stable in free-energy(+2.27eV). The presence/absence of layered type structures will be signaled by periodic patterns in atomic pair distribution functions. We propose measurements on NIMROD to help resolve this