A5034104657- Catalytic Processes in Materials Science
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Electronic and Structural Properties of Oxides
- Calcium Carbonate Crystallization and Inhibition
- Crystallization and Solubility Studies
- Iron oxide chemistry and applications
- nanoparticles nucleation surface interactions
- Catalysis and Oxidation Reactions
- Minerals Flotation and Separation Techniques
- Zeolite Catalysis and Synthesis
- Radioactive element chemistry and processing
- Advanced Thermoelectric Materials and Devices
- Nuclear Materials and Properties
- Spectroscopy and Quantum Chemical Studies
- Clay minerals and soil interactions
- Advanced Chemical Physics Studies
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Advancements in Solid Oxide Fuel Cells
- Electrocatalysts for Energy Conversion
- Glass properties and applications
- Nuclear materials and radiation effects
- Geological and Geochemical Analysis
- Ferroelectric and Piezoelectric Materials
University of Bath
2015-2024
Clave (Brazil)
2017-2020
University of Huddersfield
2019
University of Kent
2019
University of Manchester
1998-2019
Applied Mathematics (United States)
2014-2018
Engineering and Physical Sciences Research Council
2014-2018
Bath College
2014
Fondation Pour la Recherche Sur la Biodiversité
2013
University of Washington
1995-2011
Calorimetric measurements of metal adsorption energies directly provide the atoms in supported nanoparticles. As coverage increases, particles grow, revealing dependence this energy on particle size, which is found to be much stronger than predicted with usual Gibbs-Thompson relation. It shown that knowledge crucial accurately model long-term sintering rates nanoparticles catalysts.
Atomistic simulation techniques have been employed to investigate the effect of molecular adsorption water on low-index surfaces calcite, aragonite, and vaterite. Calculated surface hydration energies agree with experiment previous calculations where available. Known experimental features are reproduced, i.e., 1 × symmetry structural calcite {101̄4} bulk termination {101̄1} {112̄0} surfaces. Surface carbonate groups tend rotate lie flat in surface. The morphologies hydrated crystals...
A new simulation code for modelling extended defects e.g. linear (dislocations) and planar (surfaces grain boundaries) at the atomistic level is introduced. One of key components ability to calculate Coulombic potential a solid with one-dimensional periodicity. This approach has been applied screw dislocations in MgO we have evaluated structure (including core size) stability 〈100〉 1/2〈110〉 dislocations. The dislocation, which shortest Burgers vector, was found be more stable, as predicted...
Describes work in progress to develop a standard for interoperability among high-performance scientific components. This research stems from the growing recognition that community needs better manage complexity of multidisciplinary simulations and address scalable performance issues on parallel distributed architectures. The driving force this is need fast connections components perform numerically intensive collective interactions use multiple processes or threads. paper focuses areas we...
The lead chalcogenides represent an important family of functional materials, in particular due to the benchmark high-temperature thermoelectric performance PbTe. A number recent investigations, experimental and theoretical, have aimed gather insight into their unique lattice dynamics electronic structure. However, majority first-principles modelling has been performed at fixed temperatures, there no comprehensive systematic computational study effect temperature on material properties. We...
First-principles lattice-dynamics calculations are used to model and compare the vibrational spectra thermal transport of four bulk tin-sulphide materials.
The influence of water on the redox properties ceria is pivotal to its widespread exploitation spanning a variety applications. Ab initio simulation techniques based DFT-GGA+U are used investigate water–ceria system including associative (H2O) and dissociative (−OH) adsorption/desorption formation oxygen vacancies in presence vapor stoichiometric reduced low index surfaces at different coverages. Our calculations address controversy concerning adsorption CeO2{111}, new results reported for...
MnO2 is a technologically important material for energy storage and catalysis. Recent investigations have demonstrated the success of nanostructuring improving performance rutile in Li-ion batteries supercapacitors as catalyst. Motivated by this we investigated stability electronic structure (β-)MnO2 surfaces using density functional theory. A Wulff construction from relaxed surface energies indicates rod-like equilibrium morphology that elongated along c-axis, consistent with large number...
The layered semiconductor SnSe is one of the highest-performing thermoelectric materials known. We demonstrate, through a first-principles lattice-dynamics study, that high-temperature Cmcm phase dynamic average over lower-symmetry minima separated by very small energetic barriers. Compared to low-temperature Pnma phase, displays phonon softening and enhanced three-phonon scattering, leading an anharmonic damping low-frequency modes hence thermal transport. develop renormalization scheme...
Despite use of blended cements containing significant amounts aluminum for over 30 years, the structural nature in main hydration product, calcium aluminate silicate hydrate (C-A-S-H), remains elusive. Using first-principles calculations, we predict that is incorporated into bridging sites linear chains and at high Ca:Si H2O ratios, stable coordination number six. Specifically, silicate-bridging [AlO2(OH)4]5– complexes are favored, stabilized by hydroxyl ligands charge balancing ions...
Atomistic simulation has been used to calculate the surface structures and stability of rutile anatase polymorphs TiO 2 . The attachment energies were evaluate equilibrium pseudo-kinetic morphologies. surfaces expressed in {011}, {110}, {100} {221} with 1.85, 1.78, 2.08 2.02 J m -2 respectively. For {011} {001} dominant morphology relaxed 1.40 1.28 predicted forms largely good agreement reported experimental morphologies showed importance relaxation.
We calculated the free energy profiles of water and three metal ions (magnesium, calcium, strontium) adsorbing on [1014] calcite surface in aqueous solution. The approach uses molecular dynamics with parametrized equations to describe interatomic forces. potential model is able reproduce interactions between regardless whether they are at mineral or bulk water. simulations predict that adsorption relatively small compared enthalpy previous papers. This suggests a large change entropy...
Atomistic simulation techniques were employed to model the {0001}, {101̄0}, {101̄1}, and {101̄1̄} surfaces of α-quartz. The effect associative dissociative adsorption water onto surface structure is studied, it found that {101̄1} induces formation Si−O−Si bridges, similar those on very stable unhydrated {0001} surface. Dissociative energetically favorable all four surfaces, hydration energies agree with experiment. Surface H+ ions replaced by Na+ in two consecutive steps. Replacing only half...
A shell-model water potential, derived to be compatible with existing potential models for inorganic solids, is introduced. It reproduces experimental data of the monomer and dimer such as structure, dipole moment, binding energy. Properties liquid water, especially ordering energetics, are in adequate agreement experiment. The polarizable model used interaction MgO surfaces. Adsorption first monolayer surfaces shown disrupt next layers, leading decreased density near solid surface.
N. H. de Leeuw and S. C. Parker, J. Chem. Soc., Faraday Trans., 1997, 93, 467 DOI: 10.1039/A606573B
TiO2−B is a highly promising anode material for rechargeable lithium batteries. Computational studies based on density functional theory (DFT) have been carried out this focusing key issues relating to insertion sites and diffusion paths. Our simulation model shows good reproduction of the observed crystal structure TiO2−B. Electronic calculations suggest that lowest energy site slightly off-center position in b-axis channel low concentration (x < 0.125 LixTiO2−B). calculated cell voltages...
We employ the quasiharmonic approximation to study temperature-dependent lattice dynamics of four different phases cesium tin iodide $({\mathrm{CsSnI}}_{3})$. Within this framework, we obtain temperature dependence a number structural properties, including cell volume, bulk modulus, and Gr\"uneisen parameter. The Gibbs free energy each phase is compared against Helmholtz obtained from equilibrium structure within harmonic approximation. find that black tetragonal perovskite not dynamically...