cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb2010124
title: Local Ordering in Praseodymium/Gadolinum Co-doped Ceria MIECs

description: Gadolinium doped ceria is currently being used as an oxide ion conducting electrolyte in intermediate temperature solid oxide fuel cells (SOFCs). When co-doped with praseodymium or at lower oxygen partial pressures (pO2), these materials can also act as mixed ionic-electronic conductors (MIECs). Gd based compounds are not usually studied by neutron methods because of the high absorption cross section of natural Gd. However, using samples isotopipcally enriched with 160Gd (which has a low absorption cross section) we propose to study the local order in Gd/Pr co-doped cerias. In partciular, we seek to establish whether the samples show ordering on the anion and/or cation sublattices and whether there is evidence for dopant segration at the grain boundaries that is seen in previous studies of Pr doped ceria.
DOI: 10.5286/isis.e.rb2010124-1
title: Local Ordering in Praseodymium/Gadolinum Co-doped Ceria MIECs

description: Gadolinium doped ceria is currently being used as an oxide ion conducting electrolyte in intermediate temperature solid oxide fuel cells (SOFCs). When co-doped with praseodymium or at lower oxygen partial pressures (pO2), these materials can also act as mixed ionic-electronic conductors (MIECs). Gd based compounds are not usually studied by neutron methods because of the high absorption cross section of natural Gd. However, using samples isotopipcally enriched with 160Gd (which has a low absorption cross section) we propose to study the local order in Gd/Pr co-doped cerias. In partciular, we seek to establish whether the samples show ordering on the anion and/or cation sublattices and whether there is evidence for dopant segration at the grain boundaries that is seen in previous studies of Pr doped ceria.
DOI: 10.5286/isis.e.rb2010299
title: Analysis of the wide-angle neutron scattering of porous carbon

description: Carbons with ordered, well-defined mesopores are interesting model materials for elucidating fundamental processes such as sorption and electrochemical storage and are studied by Wide-Angle Neutron Scattering (WANS). WANS data would allow for a comparison of ordered and disordered mesoporous samples at the microstructure level. Our study shall clarify the influence of the mesoscopic confinement on the graphene stacks with respect to their microstructure. We apply the approach of Ruland/Smarsly for the evaluation of WNAS data of non-graphitic carbons, providing meaningful structural parameters describing size and disorder of the graphene stacks. Also, this analysis will be compared with PDF analysis, providing insights in the local ordering of the carbons. These data can otherwise not be obtained from standard X-rays instruments present in academic facilities and by synchrotron radiation.
DOI: 10.5286/isis.e.rb2010299-1
title: Analysis of the wide-angle neutron scattering of porous carbon

description: Carbons with ordered, well-defined mesopores are interesting model materials for elucidating fundamental processes such as sorption and electrochemical storage and are studied by Wide-Angle Neutron Scattering (WANS). WANS data would allow for a comparison of ordered and disordered mesoporous samples at the microstructure level. Our study shall clarify the influence of the mesoscopic confinement on the graphene stacks with respect to their microstructure. We apply the approach of Ruland/Smarsly for the evaluation of WNAS data of non-graphitic carbons, providing meaningful structural parameters describing size and disorder of the graphene stacks. Also, this analysis will be compared with PDF analysis, providing insights in the local ordering of the carbons. These data can otherwise not be obtained from standard X-rays instruments present in academic facilities and by synchrotron radiation.
DOI: 10.5286/isis.e.rb1720324
title: How muons see the motion of negative hydrogen ions in solids at high temperatures

description: In order to clarify the mechanism of negative hydrogen ion (hydride) conduction in solids, we wish to propose a continuation muon-spin rotation and relaxation experiment on La2LiHO3, LaSrLiH2O2, and Sr2LiH3O in the temperature range between 300 and 800 K using a furnace on EMU. According to our first muSR experiment on these compounds in the temperature range between 10 and 600 K using CCR in December 2016, a H-mu-H bond is formed even at temperatures below 400 K in LaSrLiH2O2, whereas, above 450~K, such H- starts to diffuse. However, the diffusion behavior is enhanced with temperature even at 600 K for the three compounds. Thus, particularly to clarify whether the hydride diffusion is enhanced with temperature according to a thermal activation process, we want to measure the muSR spectra at high temperatures.
DOI: 10.5286/isis.e.rb1720324-1
title: How muons see the motion of negative hydrogen ions in solids at high temperatures

description: In order to clarify the mechanism of negative hydrogen ion (hydride) conduction in solids, we wish to propose a continuation muon-spin rotation and relaxation experiment on La2LiHO3, LaSrLiH2O2, and Sr2LiH3O in the temperature range between 300 and 800 K using a furnace on EMU. According to our first muSR experiment on these compounds in the temperature range between 10 and 600 K using CCR in December 2016, a H-mu-H bond is formed even at temperatures below 400 K in LaSrLiH2O2, whereas, above 450~K, such H- starts to diffuse. However, the diffusion behavior is enhanced with temperature even at 600 K for the three compounds. Thus, particularly to clarify whether the hydride diffusion is enhanced with temperature according to a thermal activation process, we want to measure the muSR spectra at high temperatures.
DOI: 10.5286/isis.e.rb1720324-2
title: How muons see the motion of negative hydrogen ions in solids at high temperatures

description: In order to clarify the mechanism of negative hydrogen ion (hydride) conduction in solids, we wish to propose a continuation muon-spin rotation and relaxation experiment on La2LiHO3, LaSrLiH2O2, and Sr2LiH3O in the temperature range between 300 and 800 K using a furnace on EMU. According to our first muSR experiment on these compounds in the temperature range between 10 and 600 K using CCR in December 2016, a H-mu-H bond is formed even at temperatures below 400 K in LaSrLiH2O2, whereas, above 450~K, such H- starts to diffuse. However, the diffusion behavior is enhanced with temperature even at 600 K for the three compounds. Thus, particularly to clarify whether the hydride diffusion is enhanced with temperature according to a thermal activation process, we want to measure the muSR spectra at high temperatures.
DOI: 10.5286/isis.e.rb1720324-3
title: How muons see the motion of negative hydrogen ions in solids at high temperatures

description: In order to clarify the mechanism of negative hydrogen ion (hydride) conduction in solids, we wish to propose a continuation muon-spin rotation and relaxation experiment on La2LiHO3, LaSrLiH2O2, and Sr2LiH3O in the temperature range between 300 and 800 K using a furnace on EMU. According to our first muSR experiment on these compounds in the temperature range between 10 and 600 K using CCR in December 2016, a H-mu-H bond is formed even at temperatures below 400 K in LaSrLiH2O2, whereas, above 450~K, such H- starts to diffuse. However, the diffusion behavior is enhanced with temperature even at 600 K for the three compounds. Thus, particularly to clarify whether the hydride diffusion is enhanced with temperature according to a thermal activation process, we want to measure the muSR spectra at high temperatures.
DOI: 10.5286/isis.e.rb2010473
title: Neutron diffraction study on anisotropic behaviors of alpha-RuCl3 single crystals under in-plane magnetic fields

description: Alpha-RuCl3 is a two-dimensional honeycomb-lattice topological quantum magnet, in which the bond-direction dependent Kitaev exchange interaction between the strongly spin-orbit coupled Ru3+ ions with Jeff = 1/2 dominates. alpha-RuCl3 has thus attracted tremendous research interests due to its proximity to QSL. Despite that alpha-RuCl3 transforms to a long-range ordered antiferromagnetic state below TN~7 K, it has been demonstrated that this zigzag magnetic order can be suppressed by magnetic fields applied parallel to the honeycomb plane theatrically and experimentally and a quantum disorder emerges, which was proposed to be a quantum spin liquid state. Our experiment will be focused on a detailed study of anisotropic behaviors of alpha-RuCl3 single under in-plane magnetic fields.
DOI: 10.5286/isis.e.rb2010473-1
title: Neutron diffraction study on anisotropic behaviors of alpha-RuCl3 single crystals under in-plane magnetic fields

description: Alpha-RuCl3 is a two-dimensional honeycomb-lattice topological quantum magnet, in which the bond-direction dependent Kitaev exchange interaction between the strongly spin-orbit coupled Ru3+ ions with Jeff = 1/2 dominates. alpha-RuCl3 has thus attracted tremendous research interests due to its proximity to QSL. Despite that alpha-RuCl3 transforms to a long-range ordered antiferromagnetic state below TN~7 K, it has been demonstrated that this zigzag magnetic order can be suppressed by magnetic fields applied parallel to the honeycomb plane theatrically and experimentally and a quantum disorder emerges, which was proposed to be a quantum spin liquid state. Our experiment will be focused on a detailed study of anisotropic behaviors of alpha-RuCl3 single under in-plane magnetic fields.
DOI: 10.5286/isis.e.rb2010601
title: Unravelling the magnetic ground state of Dy2Zr2O7 pyrochlore: A candidate for spin ice state

description: We propose the study of magnetic ground state using muon spin resonance in pyrochlore oxide Dy2Zr2O7. We have performed the magnetic and heat capacity measurements. Our studies shows negative θ_cw ∼ -0.5 K and dominance of AFM interactions (Jnn) over the dipole-dipole FM interaction (Dnn). The ratio Jnn/Dnn∼-0.86 favors spin ice behavior. The ac susceptibility in dc applied ﬁeld shows the emergence of magnetic correlation/freezing near T ∼12 K which is akin to that observed for Dy2Ti2O7. Heat capacity results show a residual entropy of R/2ln(3/2) favouring the spin ice state. . Recent neutron study has shown some conflict results and raises doubt on the low temperature spin ice state therefore the proposed Muon experiment will help in determining the true ground state of the Dy2Zr2O7.
DOI: 10.5286/isis.e.rb2010601-1
title: Unravelling the magnetic ground state of Dy2Zr2O7 pyrochlore: A candidate for spin ice state

description: We propose the study of magnetic ground state using muon spin resonance in pyrochlore oxide Dy2Zr2O7. We have performed the magnetic and heat capacity measurements. Our studies shows negative θ_cw ∼ -0.5 K and dominance of AFM interactions (Jnn) over the dipole-dipole FM interaction (Dnn). The ratio Jnn/Dnn∼-0.86 favors spin ice behavior. The ac susceptibility in dc applied ﬁeld shows the emergence of magnetic correlation/freezing near T ∼12 K which is akin to that observed for Dy2Ti2O7. Heat capacity results show a residual entropy of R/2ln(3/2) favouring the spin ice state. . Recent neutron study has shown some conflict results and raises doubt on the low temperature spin ice state therefore the proposed Muon experiment will help in determining the true ground state of the Dy2Zr2O7.
DOI: 10.5286/isis.e.rb2010232
title: Superconducting properties of a new family of noncentrosymmetric superconductors

description: In some materials, the onset of superconductivity is accompanied by the spontaneous appearance of small magnetic fields. This is a signature of broken time-reversal-symmetry (TRS), and in several cases the origin is not understood. In our previous study we saw initial evidence of broken time reversal symmetry in a new family of superconductors using muon-spin relaxation in zero magnetic field. Here we plan to perform further measurements in both zero-field and small applied longitudinal fields to confirm whether TRS is broken. These results will help us test recent theoretical proposals to explain the occurrence of broken TRS in superconductors.
DOI: 10.5286/isis.e.rb2010232-1
title: Superconducting properties of a new family of noncentrosymmetric superconductors

description: In some materials, the onset of superconductivity is accompanied by the spontaneous appearance of small magnetic fields. This is a signature of broken time-reversal-symmetry (TRS), and in several cases the origin is not understood. In our previous study we saw initial evidence of broken time reversal symmetry in a new family of superconductors using muon-spin relaxation in zero magnetic field. Here we plan to perform further measurements in both zero-field and small applied longitudinal fields to confirm whether TRS is broken. These results will help us test recent theoretical proposals to explain the occurrence of broken TRS in superconductors.
DOI: 10.5286/isis.e.rb2010388
title: Impact of inter- and intra-molecular interactions on the collective dynamics of liquids and glass-forming systems

description: In a recent LET experiment with polarization analysis we have disentangled for the first time collective (coherent) and self (incoherent) contributions to the intensity scattered by heavy water. They behave in a strikingly different way in the region of length scales larger than the inter-molecular distances --an almost unexplored territory due to the low intensities and mixing contributions. The collective response at such mesoscales is nearly independent of scattering vector (Q), suggesting the dominance of a Q-independent mode, with the same temperature dependence as the mainly diffusive collective dynamics at inter-molecular scales. Here we will study the impact of inter- and intra-molecular interactions on the collective dynamics of liquids and glass-formers: van der Waals (e. g. tetrahydrofurane) vs H-bonds (previously studied water), and the internal connectivity (polymer melt).
DOI: 10.5286/isis.e.rb2010388-1
title: Impact of inter- and intra-molecular interactions on the collective dynamics of liquids and glass-forming systems

description: In a recent LET experiment with polarization analysis we have disentangled for the first time collective (coherent) and self (incoherent) contributions to the intensity scattered by heavy water. They behave in a strikingly different way in the region of length scales larger than the inter-molecular distances --an almost unexplored territory due to the low intensities and mixing contributions. The collective response at such mesoscales is nearly independent of scattering vector (Q), suggesting the dominance of a Q-independent mode, with the same temperature dependence as the mainly diffusive collective dynamics at inter-molecular scales. Here we will study the impact of inter- and intra-molecular interactions on the collective dynamics of liquids and glass-formers: van der Waals (e. g. tetrahydrofurane) vs H-bonds (previously studied water), and the internal connectivity (polymer melt).
DOI: 10.5286/isis.e.rb2010230
title: Phonon-related properties of the rear-earth filled skutterides: thermal-to-epithermal neutron study.

description: In our recent work, we presented a comprehensive study of the electronic structure and Fermi surface of a series of rare-earth filled skutterudites. This has shed more light on superconductivity and thermoelectric properties of these systems. With ab initio optimised unit-cell geometries and electronic structure at hand, the phonon-related properties are only one-step away, rendering studies of nuclear quantum dynamics a low-hanging fruit. Capitalising on this pre-existing body of computational work, hereby we propose to employ it even further and provide a critical appraisal and benchmarking of the phonon-related properties of the rear-earth filled skutterides, RPt4Ge12 with R = La, Ce, and Pr. The primary aim of this proposal is to exploit the correlation between atom-projected vibrational densities of states and thermoelectric figure of merit of rare-earth skutterides.
DOI: 10.5286/isis.e.rb2010230-1
title: Phonon-related properties of the rear-earth filled skutterides: thermal-to-epithermal neutron study.

description: In our recent work, we presented a comprehensive study of the electronic structure and Fermi surface of a series of rare-earth filled skutterudites. This has shed more light on superconductivity and thermoelectric properties of these systems. With ab initio optimised unit-cell geometries and electronic structure at hand, the phonon-related properties are only one-step away, rendering studies of nuclear quantum dynamics a low-hanging fruit. Capitalising on this pre-existing body of computational work, hereby we propose to employ it even further and provide a critical appraisal and benchmarking of the phonon-related properties of the rear-earth filled skutterides, RPt4Ge12 with R = La, Ce, and Pr. The primary aim of this proposal is to exploit the correlation between atom-projected vibrational densities of states and thermoelectric figure of merit of rare-earth skutterides.
DOI: 10.5286/isis.e.rb2010066
title: Spin excitations in the intrinsic magnetic topological insulator MnBi2Te4

description: Recently, the first intrinsic magnetic topological insulator has been realized in MnBi2Te4. MnBi2Te4 has a tetradymite-type structure with seven-atom layers coupled by the van der Waals interaction along the z direction (e.g., Te1-Bi1-Te2-Mn-Te3-Bi2-Te4), Its magnetic ground state is A-type antiferromagnetic phase with the out-of-plane easy axis and Neel temperature TN=25 K. Here, time-reversal symmetry is broken, but the combination of time reversal and a half-lattice translation connecting nearest spin-up and -down Mn atomic layers is not broken, giving the possible topologically nontrivial phenomena, such as topological axion state, QAH effect, two-dimensional ferromagnetism, etc. To understand the magnetic interactions and thus the interplay between magnetism and topological states in MnBi2Te4, here we propose to do inelastic neutron scattering experiment at MAPS.
DOI: 10.5286/isis.e.rb2010066-1
title: Spin excitations in the intrinsic magnetic topological insulator MnBi2Te4

description: Recently, the first intrinsic magnetic topological insulator has been realized in MnBi2Te4. MnBi2Te4 has a tetradymite-type structure with seven-atom layers coupled by the van der Waals interaction along the z direction (e.g., Te1-Bi1-Te2-Mn-Te3-Bi2-Te4), Its magnetic ground state is A-type antiferromagnetic phase with the out-of-plane easy axis and Neel temperature TN=25 K. Here, time-reversal symmetry is broken, but the combination of time reversal and a half-lattice translation connecting nearest spin-up and -down Mn atomic layers is not broken, giving the possible topologically nontrivial phenomena, such as topological axion state, QAH effect, two-dimensional ferromagnetism, etc. To understand the magnetic interactions and thus the interplay between magnetism and topological states in MnBi2Te4, here we propose to do inelastic neutron scattering experiment at MAPS.
DOI: 10.5286/isis.e.rb2010110
title: Negative muons as a probe of magnetic oxides

description: Muon research has almost exclusively utilised positive muons and they have proven to be an effective local probe of magnetism. However, negative muons offer some interesting advantages because the probe site is known: the negative muons stop close to the nucleus of each atom in the sample. The signals from different atoms can be distinguished because the lifetime depends on the atomic number. We propose a study of two prototypical magnetic oxides in which we will focus on the signals from the mu-O site. The planned experiments will support the technical developments on both the hardware and software side at ISIS which will be carried out in the long shutdown. This new development is centred around an ISIS Facility Studentship and this beam time will be an integral part of this project.
DOI: 10.5286/isis.e.rb2010110-1
title: Negative muons as a probe of magnetic oxides

description: Muon research has almost exclusively utilised positive muons and they have proven to be an effective local probe of magnetism. However, negative muons offer some interesting advantages because the probe site is known: the negative muons stop close to the nucleus of each atom in the sample. The signals from different atoms can be distinguished because the lifetime depends on the atomic number. We propose a study of two prototypical magnetic oxides in which we will focus on the signals from the mu-O site. The planned experiments will support the technical developments on both the hardware and software side at ISIS which will be carried out in the long shutdown. This new development is centred around an ISIS Facility Studentship and this beam time will be an integral part of this project.
DOI: 10.5286/isis.e.rb2010823
title: A muSR study of single crystals of the superconductor beta-PdBi2

description: Beta-PdBi2 is an intrinsically bulk superconducting topological metal. Despite a large number of experimental and theoretical works, the nature and microscopic origin of superconducting state in beta-PdBi2 is still under hot debate. Unresolved issues concerning the multigap superconductivity and the role of the topological surface state in the superconductivity make beta-PdBi2 an important system to study using musr technique. Furthermore, signatures of unconventional bulk superconductivity have also been reported recently in K-doped beta-PdBi2. It was predicted that the K-doped beta-PdBi2 is likely to be a 3D bulk topological superconductor and could undergo a topological superconducting phase transition between a trivial (undoped) and a topological (doped) superconductor. Here we propose to study the superconducting properties both undoped and doped beta-PdBi2 using the muSR technique.
DOI: 10.5286/isis.e.rb2010823-1
title: A muSR study of single crystals of the superconductor beta-PdBi2

description: Beta-PdBi2 is an intrinsically bulk superconducting topological metal. Despite a large number of experimental and theoretical works, the nature and microscopic origin of superconducting state in beta-PdBi2 is still under hot debate. Unresolved issues concerning the multigap superconductivity and the role of the topological surface state in the superconductivity make beta-PdBi2 an important system to study using musr technique. Furthermore, signatures of unconventional bulk superconductivity have also been reported recently in K-doped beta-PdBi2. It was predicted that the K-doped beta-PdBi2 is likely to be a 3D bulk topological superconductor and could undergo a topological superconducting phase transition between a trivial (undoped) and a topological (doped) superconductor. Here we propose to study the superconducting properties both undoped and doped beta-PdBi2 using the muSR technique.
DOI: 10.5286/isis.e.rb2010452
title: Characterising temperature dependent morphological changes to thermosensitive semiconducting polymer nanoparticles for drug delivery

description: We have synthesised a series of novel semiconducting polymer nanoparticles (SPNs) for photothermal therapy. Characterising changes to their morphology upon heating is crucial for elucidating how they can be applied to effectively deliver encapsulated cargo to cancer cells. Here we propose i) a series of experiments over a wide temperature range to capture the changes in SPN morphology upon heating, and ii) contrast matching experiments to study the intra-particle location of an encapsulated drug and its release profile. The results will provide key mechanistic insights into the application of these particles for cancer therapeutics which are not possible by other techniques.