A5054427905- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- High-pressure geophysics and materials
- Crystallography and molecular interactions
- Metal-Organic Frameworks: Synthesis and Applications
- Crystal Structures and Properties
- Supramolecular Self-Assembly in Materials
- Supramolecular Chemistry and Complexes
- Advanced Chemical Physics Studies
- Fuel Cells and Related Materials
- Astro and Planetary Science
- Magnetic and transport properties of perovskites and related materials
- Molecular Junctions and Nanostructures
- Advanced Condensed Matter Physics
- Methane Hydrates and Related Phenomena
- Covalent Organic Framework Applications
- Spacecraft and Cryogenic Technologies
- Nuclear materials and radiation effects
- Nuclear Physics and Applications
- Spectroscopy and Quantum Chemical Studies
- Pesticide Exposure and Toxicity
- Industrial Gas Emission Control
- Rare-earth and actinide compounds
- Thermal Expansion and Ionic Conductivity
- Pesticide and Herbicide Environmental Studies
Atomic Weapons Establishment
2018-2021
Reading Museum
2021
University of Liverpool
2017-2020
Diamond Light Source
2014-2019
Rutherford Appleton Laboratory
2014-2019
Liverpool Hospital
2017-2018
University of Edinburgh
2012-2015
We present an in situ powder X-ray diffraction study on the phase stability and polymorphism of metal-organic framework ZIF-4, Zn(imidazolate)2, at simultaneous high pressure temperature, up to 8 GPa 600 °C. The resulting pressure-temperature diagram reveals four, previously unknown, high-pressure-high-temperature ZIF phases. crystal structures two new phases-ZIF-4-cp-II ZIF-hPT-II-were solved by methods. total energy ZIF-4-cp-II was evaluated using density functional theory calculations...
Abstract Many interesting target guest molecules have low symmetry, yet most methods for synthesising hosts result in highly symmetrical capsules. Methods of generating lower symmetry pores are thus required to maximise the binding affinity host–guest complexes. Herein, we use mixtures tetraaldehyde building blocks with cyclohexanediamine access low‐symmetry imine cages. Whether a low‐energy cage is isolated can be correctly predicted from thermodynamic preference observed computational...
Porous materials can be used as sorbents for the bulk uptake (and potential deactivation) of chemical warfare agents (CWAs).
Resistively heated diamond-anvil cells have been used together with synchrotron x-ray diffraction to investigate the phase diagram of calcium up 50 GPa and 800 K. The boundaries between Ca-I (fcc), Ca-II (bcc), Ca-III (simple cubic, sc) phases determined at these pressure-temperature conditions, ambient temperature equation state has generated. parameters from experimental compression curve observed by using third-order Birch-Murnaghan Vinet equations. A thermal was also for combining...
A range of nitrogen containing bases was tested for the hydrolysis a nerve agent simulant, methyl paraoxon (MP), and chemical warfare agents, GB VX. The product distribution found to be highly dependant on basicity base quantity water used hydrolysis. This study is important in design decontamination technology, which often involve mimics CWAs.
The phase diagram of zinc (Zn) has been explored up to 140 GPa and 6000 K, by combining optical observations, x-ray diffraction, ab initio calculations. In the pressure range covered this study, Zn is found retain a hexagonal close-packed (hcp) crystal symmetry melting temperature. known decrease axial ratio (c/a) hcp under compression observed in diffraction experiments from 300 K at which c/a reaches (≈10 GPa) slightly affected When reached, we that single crystals Zn, formed high...
Abstract Many interesting target guest molecules have low symmetry, yet most methods for synthesising hosts result in highly symmetrical capsules. Methods of generating lower symmetry pores are thus required to maximise the binding affinity host–guest complexes. Herein, we use mixtures tetraaldehyde building blocks with cyclohexanediamine access low‐symmetry imine cages. Whether a low‐energy cage is isolated can be correctly predicted from thermodynamic preference observed computational...
Water and ammonia are considered major components of the interiors giant icy planets their satellites, which has motivated exploration under high P-T conditions. Exotic forms these pure ices have been revealed at extreme (~megabar) pressures, notably symmetric, ionic, superionic phases. Here we report on an extensive experimental computational study high-pressure properties monohydrate compound forming from equimolar mixture water ammonia. Our experiments demonstrate that relatively mild...
The structure of the crystalline ammonia-bearing phase formed when ammonia monohydrate liquid is compressed to 3.5(1) GPa at ambient temperature has been solved from a combination synchrotron x-ray single-crystal and neutron powder-diffraction studies. solution reveals that rather than having (AMH) composition as had previously thought, an hemihydrate composition. monoclinic with spacegroup P21/c lattice parameters = 3.3584(5) Å, b 9.215(1) c 8.933(1) Å β 94.331(8)° GPa. atomic arrangement...
The disordered-molecular-alloy phase (DMA) of ammonia hydrates [J. S. Loveday and R. J. Nelmes, Phys. Rev. Lett. 83, 4329 (1999)] is unique in that it has substitutional disorder water over the molecular sites a body centred cubic lattice. Whilst this structure been observed di- mono-hydrate compositions, not conclusively hemihydrate system. This work presents investigations structural behaviour as function P T. indications earlier studies [Ma et al. RSC Adv. 2, 4290 (2012)] DMA could be...
Vanadium is reported to undergo a pressure-induced bcc-rhombohedral phase transition at 30--70 GPa, with pressure that sensitive the hydrostaticity of sample environment. However, experimental evidence for structure high-pressure being rhombohedral surprisingly weak. We have restudied vanadium under 154 GPa using both polycrystalline and single-crystal samples, variety different transmitting media (PTM). find only when samples does one observe phase; diffraction profiles from do not fit...
Here we report a high-pressure investigation into the structural and magnetic properties of double perovskite La2NiMnO6 using neutron scattering over temperature range 4.2-300 K at ambient pressure 120-1177 up to maximum 6.6 GPa. X-ray diffraction was also used 64 GPa, 300-720 K. The sample found exist in mixed rhombohedral/monoclinic symmetry conditions, balance which be strongly temperature- pressure-dependent. Alternating current magnetometry absorption near-edge structure measurements...
We describe the high-pressure (4 GPa) high-temperature (∼1100 K) synthesis of solid solution series SeCo 1-x MnxO 3 (0 < x 1) using H 2 SeO 4 and transition metal oxide mixtures sealed in Pt capsules.Neutron powder diffraction has been performed to determine progression structure across solution.All samples crystallise with orthorhombic P nma symmetry, octahedral tilting is determined increase Mn content.SQUID magnetometry measurements were performed, reveal that Néel temperature shifts only...
The authors would like to draw attention an error in Figure 5 of this Research Article. top line does not show the correct cage ([L1+2B1]); rather, [L1+2B1N] has been shown twice. corrected figure is below. This mistake affect scientific conclusions paper. Side-, window-, and top-views electrostatic potential inside cavities socially sorted [L1+2B1X] cages, mapped onto 0.0004 a.u. total electron density isosurface calculated at M06-2X/6-311+G(d,p) level theory.
Both the trigonal (Berlinite-type, phase-I), and orthorhombic (CrVO<sub>4</sub>-type, phase-II) forms of FePO<sub>4</sub>have been studied at high-pressure using neutron powder diffraction.
The behaviour of gas hydrates at high pressure is wide interest and importance. Gas are stablised by water-gas repulsive interactions. Information on the effect changing density these interactions provides fundamental insight into nature water potential. also widely found in systems like ammonia-water methane-water form basis 'mineralogy' planetary bodies Saturn's moon Titan. Finally, offer possibility cheap environmentally inert transportation storage for gases carbon dioxide hydrogen. We...
The structural transformation of FePO4 from the trigonal berlinite phase to orthorhombic CrVO4 has been studied using neutron diffraction at high pressure and high-temperature. structure was compressed a 5.2(2) GPa amorphisation observed. Upon annealing temperatures above 798(28) K observed form. This lowers formation temperature required promote this over amorphous by ∼100 compared previous reports. No other structured phases were during process which implies that is most stable form...
Many interesting target guest molecules have low symmetry, yet most methods for synthesising hosts result in highly symmetrical capsules. Methods of generating lower-symmetry pores are thus required to maximise the binding affinity host-guest complexes. Here, we use mixtures tetraaldehyde building blocks access low-symmetry imine cages. Whether a low-energy cage is isolated can be correctly predicted from thermodynamic preference observed computational models. The stability structures...