Group Members

Principle Investigators:

Dr. Rebecca Boston
Dr. Julian Dean
Dr. Colin L. Freeman
Prof. SC Lenny Koh
Dr. Nicola Morley
Image result for ian m reaney sheffield
Prof. Ian M. Reaney
Prof. Derek C. Sinclair
Dr. Fan Yang

PhD Students:

Principle Investigators:

Dr Rebecca Boston is a Lloyd’s Register/ Royal Academy of Engineering Research Fellow. She originally joined the department in 2014 as a postdoctoral research associate on the Substitution and Sustainability grant, before being awarded the Fellowship which started in December 2016. Rebecca did her PhD at the Bristol Centre for Functional Nanomaterials at the University of Bristol, working with Dr Simon Hall in the School of Chemistry. Her work is focussed on the use of novel synthetic templating methods (biological, solvent etc) to control the structure-function relationships in a variety of materials, including n-type thermoelectrics, high permittivity materials, and Li- and Na-ion batteries. She also works on the development of Cold Sintering techniques for ceramic materials, and has an interest in analytic transmission electron microscopy.

Recent Papers

1) R. Boston, Z. Schnepp, Y. Nemoto, Y. Sakka, S. R. Hall, Science (2014), 344, 623-626.

In Situ TEM observation of a microcrucible mechanism of nanowire growth.

The growth of metal oxide nanowires can proceed via a number of mechanisms such as screw dislocation, vapour-liquid-solid process, or seeded growth. Transmission electron microscopy (TEM) can resolve nanowires but invariably lacks the facility for direct observation of how nanowires form. We used a transmission electron microscope equipped with an in situ heating stage to follow the growth of quaternary metal oxide nanowires. Video-rate imaging revealed barium carbonate nanoparticles diffusing through a porous matrix containing copper and yttrium oxides to subsequently act as catalytic sites for the outgrowth of Y2BaCuO5 nanowires on reaching the surface. The results suggest that sites on the rough surface of the porous matrix act as microcrucibles and thus provide insights into the mechanisms that drive metal oxide nanowire growth at high temperatures.

2) R. Boston, W. L. Schmidt, G. D. Lewin, A. C. Iyasara, Z. Lu, H. Zhang, D. C. Sinclair, I. M. Reaney, Chem Mater. (2017), 29, 265-280.

Protocols for the Fabrication, Characterization, and Optimization of n-Type Thermoelectric Ceramic Oxides

The development of oxides with high figure of merit, ZT, at modest temperatures (∼300–500 °C) is desirable for ceramic-based thermoelectric generator technology. Although ZT is a compound metric with contributions from thermal conductivity (κ), Seebeck coefficient (S), and electrical conductivity (σ), it has been empirically demonstrated that the key to developing thermoelectric n-type oxides is to optimize σ of the ceramic to ∼1000 S/cm at the operating temperature. This paper covers common aspects of ceramic processing: the potential pitfalls and how to avoid them. The problems associated with measuring κ, σ, and S to achieve reproducible and accurate values of ZT are discussed, as are future directions which should enable further optimization. Finally, we comment on how these protocols may be applied to other systems and structures.

3) R. Boston, P. Y. Foeller, D. C. Sinclair, I. M. Reaney, Inorg. Chem. (2017), 56, 542-547.

Synthesis of Barium Titanate Using Deep Eutectic Solvents

A deep eutectic solvent of malonic acid and choline chloride has been used to synthesize ferroelectric barium titanate. The barium titanate forms at 950 °C, mediated by the intermediate phases barium chloride and titanium dioxide. The materials sinter at a lower temperature than the solid-state equivalent while retaining comparable properties. This synthesis represents a flexible and widely applicable method which can be applied to a range of functional materials to produce nanoscale powders.

Dr Julian Dean is a Senior Lecturer in the Department of Materials Science and Engineering (MSE) at the University of Sheffield (UoS) after being appointed lecturer in September 2013. He obtained a first class degree in Physics and completed his PhD in 2007 on the development of magnetic micro-electro-mechanical systems (magMEMS) for sensory applications (both UoS). He then worked as a PDRA on number of projects, developing software packages with industrial and academic partners before becoming a teaching associate in 2011. He has published over 47 articles on functional materials in leading journals and peer-reviewed conference proceedings (h-index of 13). Julian's main area of expertise is in developing FE packages and microstructure generation for prediction and analysis of magnetic and ferroelectric systems working with companies such as AvX and Siemens wind power. Using experience gained in developing packages for magnetic systems, Julian has developed an FEM package capable of simulating Maxwell’s equations in both space and time. This can predict the electric response of functional oxide ceramic materials for a given microstructure and set of material propertie. A simple core shell structure is predicted to generate an inhomogeneous current density leading to a non-Debye like response in the impedance spectra. We have shown how the electrical microstructure can be manipulated by control of the physical microstructure leading to the successful ability to predict the optimisation of materials for multi-layered ceramic capacitors. The latter publication being an invited article for “Emerging Investigators 2016: Novel design strategies for new functional materials” in the RSC Journal of Materials Chemistry A. This has also led to three invited talks (ICE2015 (Am., Asian and Eur. Ceram. Socs, Penn State, USA), SSC2015 (Royal Soc. Chem (RSC), Kent, UK), EMA2016 (Am. Ceram. Soc, Florida, USA)).

Recent Papers

1) Design of a bilayer ceramic capacitor with low temperature coefficient of capacitance, PY Foeller, JS Dean, IM Reaney, DC Sinclair, Applied Physics Letters 109 (8), 082904 (2016)

2) Carbon uptake and distribution in Spark Plasma Sintering (SPS) processed Sm (Co, Fe, Cu, Zr), AJ Mackie, GD Hatton, HGC Hamilton, JS Dean, R Goodall, Materials Letters 171, 14-17 1 (2016)

3) A resource efficient design strategy to optimise the temperature coefficient of capacitance of BaTiO 3-based ceramics using finite element modelling, JS Dean, PY Foeller, IM Reaney, DC Sinclair, Journal of Materials Chemistry A 4 (18), 6896-6901, 1 (2016)

4) A sound idea: Manipulating domain walls in magnetic nanowires using surface acoustic waves, J Dean, MT Bryan, JD Cooper, A Virbule, JE Cunningham, TJ Hayward, Applied Physics Letters 107 (14), 142405, 1 (2015)

Dr Colin L. Freeman is a lecturer in Materials Simulation. He specialises in atomic scale simulations using both classical and quantum methods to study a range of different material systems including minerals, molecules, metals, biominerals and functional ceramics. He has pioneered research into studying mineral-molecular interfaces, understanding highly disordered ceramic systems and developing forcefields to study these systems. He has over 50 publications in a range of prestigious journals including Nature Materials and Advanced Functional Materials, which have received over 1000 citations. Within functional materials Colin focusses on simulations to understand the properties and growth of these materials from the atomic scale up.

Recent Papers

1) Kim, Y.Y., Carloni, J.D., Demarchi, B., Sparks, D., Reid, D.G., Kunitake, M.E., Tang, C.C., Duer, M.J., Freeman, C.L., Pokroy, B., Penkman, K., Harding, J.H., Estro, L.A., Baker, S.P., Meldrum, F.C. (2016) Tuning hardness in calcite by incorporation of amino acids Nature Materials 15 (8), 903-U153. DOI: 10.1038/NMAT4631

2) Dawson, J. A., Sinclair, D. C., Harding, J. H., Freeman, C. L. (2014). A-site strain and displacement in Ba1−xCaxTiO3 and Ba1−xSrxTiO3 and the consequences for the curie temperature.Chemistry of Materials, 26(21), 6104-6112. doi:10.1021/cm502158n

2) Freeman, C. L., Dawson, J. A., Chen, H. -R., Ben, L., Harding, J. H., Morrison, F. D., West, A. R. Sinclair D. C. (2013). Energetics of donor-doping, metal vacancies, and oxygen-loss in A-site rare-earth-doped BaTiO 3 . Advanced Functional Materials, 23(31), 3925-3928. doi:10.1002/adfm.201203147

Professor SC Lenny Koh (H index 48) is a senior Chair professor of Operations Management and a former Associate Dean at the Sheffield University Management School, and currently Directors of three research centres, i.e. LSCM, CEES and AREC at The University of Sheffield. She holds a First-class honours degree in Industrial and Manufacturing Systems Engineering, and a Doctorate in Operations Management. She is an internationally renowned authority on supply chain with a focus on low carbon and sustainability. Her research is recognised for its scientific novelty and has generated major impacts for society, industry and government. Her interdisciplinary approaches have advanced the understanding and resolution of complex supply chain problems with supply chain life cycle thinking and have transcended resource efficiency and resource sustainability across disciplines. She has more than 308 publications, and has generated about £40M of career research incomes.

Dr Nicola Morley is a senior lecturer (since 2013) in Functional Magnetic Materials, within the department of Materials Science and Engineering, University of Sheffield. Her main research areas are the development of magnetostrictive films for MEMS devices, organic spintronics, magnetocaloric materials and multiferrroics. The research on magnetocaloric materials has investigated using novel processing techniques such as SPS to produce competitive materials for commercial applications, this work was done in collaboration with Camfridge. Other research highlights include work on organic spintronics studying the interface between organic semiconductors and magnetic materials, the development of highly magnetostrictive Fe-based thin films (Fe-Ga and Fe-Co) for applications including strain and mass sensors, and recently voltage control of ferroelectric/ferromagnetic structures. She has published over 50 papers, including 3 nature materials papers. She is currently the Sheffield PI on a H2020 Cleansky2 project (lead Imperial College; total funding 7.2 million euros), Co-I on a £2.5m Materials Sustainability grant (L017563) and a £0.5m TSB water sensor grant. As well as having been PI on 2 EPSRC grants (F023499 and D022509), along with grants from the Royal Academy of Engineering, Royal Society and the British Council. She is also an active user of central facilities (ISIS, UK; ESRF, France) and sat on the Muon FAP panel. She is a twinning partner on the FP7-NANOSENS project based in Iasi, Romania and a collaborator on a French National Research Agency grant based in Strasbourg, France.

Recent Papers

1) K. Wang, P. Murahari, K. Yokoyama, J. S. Lord, F. L. Pratt, J. he, L. Schulz, M. Willis, J. E. Anthony, N. A. Morley, L. Nuccio, A. Misquitta, D. J. Dunstan, K. Shimomura, I. watanabe, S. Zhang, P. Heathcote and A. J. Drew, online Nature Materials, (2016)

This paper presents the first photo muon spectroscopy measurements of temporal and spatial photochemical reactivity of an organic semiconductor between light off and on states. The technique is ground breaking as it's spatial resolution is to a single carbon atom, thus is able to probe the dynamics of molecular excitations and photochemistry.

2) V. Iurchuk, D. Schick, J. Bran, D. Colson, A. Forget, D. Halley, A. Koc, M. Reinhardt, C. Kwamen, N. A. Morley, M. Bargheer, M. Viret, R. Gumeniuk, B. Doudin and B. Kundys, Physical Review Letters, 117, 107403, (2016)

This paper describes the novel use of light to change the strain state of a ferroelectric/ferromagnetic (FE/FM) heterostructure. The light is used to write a new permanent magnetic state to the FM layer by changing the strain state of the FE layer. The original magnetic state is recovered by the application of a voltage to the FE layer. These heterostructures offer a low power alternative to existing current based magnetic switching systems.

3) W-G Yang, N A Morley, J Sharp, Y Tian and W M Rainforth, Applied Physics Letters, 108, 012901, (2016)

This paper studies how thin Ti layers change the magnetoelectric coupling between ferroelectric and ferromagnetic layers. It was found that the Ti layer changed the texture of the ferromagnetic layer, thus the ferromagnetic anisotropy changed from uniaxial to isotropic, allowing the magnetoelastic anisotropy to dominate. Thus on applying a voltage to the ferroelectric layer, changed the ferromagnetic magnetisation from an easy axis to a hard axis, as well as increase the magnetoelectric coupling. The change in magnetisation on the application of an applied voltage is repeatable, thus provides a low power alternative to current based magnetic switch devices.

4) N A Morley, R Dost, A S L Lingam and A Barlow, Applied Surface Science, 359, 704-713, (2015)

This paper investigates how the interface between conjugate polymers and magnetic thin films influences the magnetic anisotropy and the spin current. It was determined that the polymer morphology changes the magnetic layer anisotropy, such that both uniaxial and isotropic films were measured. It was also determined that the sulphur and carbon within the polymers interacted with the magnetic layer to form new species at the interface. These new species will affect the spin injection between the layers. The results are important in the design of organic spin devices, so to achieve a large spin current within the device, hence increase sensitivity.

Professor Ian M. Reaney joined the Department of Materials Science and Engineering in 1994, as a PDRA, then as a Lecturer from 1995 followed by eventual promotion to Professor in 2007. Ian was appointed to the Dyson Chair in Ceramics at the Materials Science and Engineering at the University of Sheffield in January 2017. He is also an Adjunct Professor at Pennsylvania State University, USA and at the University of Aveiro, Portugal. Ian has been awarded over £20M in career income for engineering research. His 300 scientific papers receive 1100 citations per year (more than 10,000 total citations), 23 papers having over 100 citations. He has given over 25 invited presentations a major conferences in the last 5 years. His career H-index = 52 (H5 = 38) (Googlescholar). He won 'best Knowledge Transfer Partnership based on EPSRC funded research’, 2008 and was the recipient of the Edward C. Henry award for best paper in the J. American Ceramics Society (Electronic Division) 2001.

Recent Papers

1) Integrated hybrid life cycle assessment and supply chain environmental profile evaluations of lead-based (lead zirconate titanate) versus lead-free (potassium sodium niobate) piezoelectric ceramics, T Ibn-Mohammed, SCL Koh, IM Reaney, A Acquaye, D Wang, S Taylor, Energy & Environmental Science 9 (11), 3495-3520, 2016

Potassium sodium niobate (KNN) has been speculated to have better environmental credentials and is considered as a “greener” replacement to lead zirconate titanate (PZT) based piezoelectric ceramics. Against this backdrop, life cycle supply chain assessment (LCA) was undertaken which revealed that the presence of niobium in KNN constitutes far greater impact across all the 16 categories considered in comparison with PZT. The increased environmental impact of KNN occurs in the early stages of the LCA due to raw material extraction and processing. As a result, the environmental damage has already occurred before its use in piezoelectric applications during which it doesn't constitute any threat. As such, the use of the term “environmentally friendly” for the description of KNN should be avoided. 

2) High-Figure-of-Merit Thermoelectric La-Doped A-Site-Deficient SrTiO3 Ceramics, Z Lu, H Zhang, W Lei, DC Sinclair, IM Reaney, Chemistry of Materials 28 (3), 925-935, 2016.

This article defines a methodology for improving the ZT values in oxide based thermoelectrics. Thermoelectrics are an emerging technology that threaten to be a game changer in increasing the fuels efficiencies in the automotive and aerospace industries. The methodologies were applied to La doped SrTiO3 and effectively doubled the fundamental ZT of the lattice. The improvements in ZT directly relate to the complex structural and defect chemistry associated with ionic compensation in through the formation of A-site vacancies according to the equation (Sr1–3x/2LaxTiO3).

3) A crystal-chemical framework for relaxor versus normal ferroelectric behavior in tetragonal tungsten bronzes, X Zhu, M Fu, MC Stennett, PM Vilarinho, I Levin, CA Randall, J Gardner, FD Morrison, IM Reaney, Chemistry of Materials 27 (9), 3250-3261, 2015

This contribution defines structure property relations in an important class of ferroic oxides, tetragonal tungsten bronzes (TTBs). It collates and makes sense of over 60 years of research in TTBs and identifies a simple unifying crystallochemical model to determine the principle dielectric behaviour. It predicts new properties of new compounds and explains all previously determined dielectric data in this important class of oxides.

4) Temperature stable and fatigue resistant lead-free ceramics for actuators, A Khesro, D Wang, F Hussain, DC Sinclair, A Feteira, IM Reaney, Applied Physics Letters 109 (14), 142907, 2016

Lead-free ceramics with the composition 0.91K1/2Bi1/2TiO3–0.09(0.82BiFeO3-0.15NdFeO3-0.03Nd2/3TiO3) were prepared using a conventional solid state, mixed oxide route. The ceramics exhibited a high strain of 0.16% at 6 kV mm−1, stable from room temperature to 175 °C, with a variation of less than 10%. The materials were fabricated into multilayer structures by co-firing with Pt internal electrodes. The prototype multilayer actuator exhibited constant strains up to 300 °C with a variation of ∼15%. The composition showed fatigue resistant behaviour in both monolithic and multilayer form after bipolar loading of 106 cycles.

Professor Derek C. Sinclair was appointed as a lecturer in functional materials at the University of Sheffield in 1999 and promoted to a chair in Materials Chemistry in 2008. Previously he held lecturer appointments at the Department of Chemistry, University of Aberdeen (1994-99) and the Department of Materials Science, University of Leeds (1993-94). Derek has been involved in synthesis and characterisation of functional materials and devices for more than 25 years spanning a wide spectrum of functionality from polar dielectrics, n-type thermoelectrics and high Tc superconductors to mixed electronic/ionic conductors and solid electrolytes. He has been awarded more than £ 20 M in research income, has more than 200 refereed papers; H index = 48 (more than 10,000 citations, Google Scholar) and 12 invited talks at International conferences in the last 3 years. He is an Editor for the Journal of the Asian Ceramic Societies (JAsCerS) for the Ceramic Societies of Japan and Korea.

Recent Papers

1. J.S. Dean, P. Y. Foeller, I. M. Reaney and D. C. Sinclair, A resource efficient design strategy to optimise the temperature coefficient of capacitance of BaTiO3-based ceramics using finite element modelling, Journal of Materials Chemistry A, 4 (2016) 6896-6901

2. F. Yang, H. Zhang, L. Li, I. M. Reaney and D. C. Sinclair, High ionic conductivity with low degradation in A-site Strontium-doped nonstoichiometric Sodium Bismuth Titanate perovskite, Chemistry of Materials, 28 (2016) 5269-5273

3. R. Boston, W. L. Schmidt, G. D. Lewin, A. C. Iyasara, Z. Lu, H. Zhang, D. C. Sinclair and I. M. Reaney, Protocols for the Fabrication, characterization, and optimization of n‑type thermoelectric ceramic oxides, Chemistry of Materials, [DOI: 10.1021/acs.chemmater.6b03600]

Postdoctoral Research Fellows:

Dr Christopher Handley joined the Department, under the SUbST grant, working with both the MESAS (Multiscale Engineering and Science Simulations at Sheffield) and the Functional Materials and Devices group, in May 2015. His work focuses on the design of novel forcefields – a method of modelling chemistry using classical mechanics, rather than using more expensive quantum mechanical simulations - for the simulation of photovoltaic materials, and solid oxide ion conductors – a materials that has applications for fuel cells. Chris’ work in conjunction with synthetic material scientists, aims at making solar energy cheaper and more available. Chris uses modern computing power to develop next generation forcefields and he has focused primarily on the use of machine learning methods that can discover these forcefields, by learning the relationships between atomic positions, and the properties of the material. He employs ‘machine learning’, where the computer programme can learn from vast amounts of quantum mechanical simulations, with the end goal being forcefields that give quantum mechanical accuracy, but for the fraction of the computer time.

Recent Papers

1) A new potential for Methylammonium Lead Iodide, CM Handley, CL, Freeman, Physical Chemistry Chemistry Physics, 2016, DOI: 10.1039/C6CP05829A

We present a new set of interatomic potentials for modelling Methylammonium Lead Iodide. The potential model uses existing potentials for lead iodide and methylammonium, and new functions are fitted to enable these pre-exisiting potentials to be used together, while still be capable of modelling lead iodide and methylammonium iodide as spearate materials. Fitting was performed using a combination of ab initio, and experimental reference data. The model is tested by simulating methylammonium lead iodide at a range of temperatures. Our simulations are in agreement with experiment and reveal the short and long range ordering of the molecular cations and lead iodide octahedra.

2) Next generation interatomic potentials for condensed systems, CM Handley, J Behler, Eur. Phys. J. B, 87, 152, 2014 

The computer simulation of condensed systems is a challenging task. While electronic structure methods like density-functional theory (DFT) usually provide a good compromise between accuracy and efficiency, they are computationally very demanding and thus applicable only to systems containing up to a few hundred atoms. Unfortunately, many interesting problems require simulations to be performed on much larger systems involving thousands of atoms or more. Consequently, more efficient methods are urgently needed. In recent years, several novel types of potentials have emerged, which are not based on physical considerations. Instead, they aim to reproduce a set of reference electronic structure data as accurately as possible by using very general and flexible functional forms. In this review we will survey a number of these methods. While they differ in the choice of the employed mathematical functions, they all have in common that they provide high-quality potential-energy surfaces, while the efficiency is comparable to conventional empirical potentials. It has been demonstrated that in many cases these potentials now offer a very interesting new approach to study complex systems with hitherto unreached accuracy.

keywords: forcefields, machine learning, density functional theory, photovoltaic, solid oxide solid state fuel cells

Dr Taofeeq Ibn-Mohammed is a Senior Research Associate at the Centre for Energy, Environment and Sustainability and the Advanced Resource Efficiency Centre, both at The University of Sheffield, UK. He works as part of a cross-functional team of experts on an exciting Engineering and Physical Science Research Council (EPSRC) funded project titled: Substitution and Sustainability in Functional Materials and Devices Sector. He holds a PhD in Energy Systems Engineering and Policy Analysis, which stems from research in engineering, energy, environment and economics in the context of climate change and sustainability. He also holds a Master’s Degree in Applied Instrumentation and Control (Distinction) and a Bachelor’s Degree in Electrical and Electronics Engineering. Taofeeq is an enthusiastic and early career research scholar and possess very strong numerical modelling, quantitative and analytical skills and believes in the positive impact that the theoretical rigor of research can have on policy, practice and academia. He is a reviewer for top academic journals, including Energy and Buildings, Building and Environment and, Renewable and Sustainable Energy Reviews. He has more than thirteen years of experience covering energy and sustainability, IT/telecommunications and academia with a multi-disciplinary perspective, integrating technical, economic, environmental, energy and policy issues. Taofeeq has published widely on energy and sustainability-related research and his current research areas include energy systems engineering and lifecycle supply-chain modelling in the context of advanced functional materials.

Recent Papers

1) Drivers of US toxicological footprints trajectory 1998–2013., SCL Koh, T Ibn-Mohammed, A Acquaye, K Feng, IM Reaney, K Hubacek, H Fujii, K Khatab, Scientific Reports 2016, 6, 39514.

2) Integrated hybrid life cycle assessment and supply chain environmental profile evaluations of lead-based (lead zirconate titanate) versus lead-free (potassium sodium niobate) piezoelectric ceramics, T Ibn-Mohammed, SCL Koh, IM Reaney, A Acquaye, D Wang, S Taylor, A Genovese, Energy & Environmental Science 2016, 9, (11), 3495-3520.

3) A Acquaye, K Feng, E Oppon, S Salhi, T Ibn-Mohammed, A Genovese, K Hubacek, Measuring the Environmental Sustainability Performance of Global Supply Chains: a Multi-Regional Input-Output analysis for Carbon, Sulphur Oxide and Water Footprints. Journal of Environmental Management 2016.

Dr Giorgio Schileo is a KTP Associate working in collaboration with Dyesol UK. He obtained his PhD from Sheffield Hallam University with a thesis on composite multiferroic ceramics in 2014. After a short postdoc at the Department under the SUbST grant working on new organic-inorganic perovskite PV materials in collaboration with Dyesol UK Ltd, he was later appointed KTP Associate in the same company in January 2015. His research focuses on the industrial application of materials chemistry to develop cheap and reliable solar cells. The photoactive materials in these 4th generation-solar cell technology are the so called hybrid halide perovskites, which have received an incredible amount of attention in the last three years due to their low cost, ease of fabrication and high efficiency. However, numerous issues have to be solved before a complete panel can be commercialised. Giorgio's research activity transfer the expertise of the Academia into the forefront of Industrial R&D at Dyesol, with the aim of developing a cheap alternative to silicon-based solar panels.

Dr Whitney L. Schmidt joined the Functional Materials and Devices group at the University of Sheffield in June 2015 and holds a Postdoctoral Research Associate position on the SUbST grant. Her research here is focused on energy harvesting materials in the areas of photovoltaics and thermoelectrics. She is currently characterizing the family of organometal lead halide perovskites, a hot topic in the field of photovoltaics, and tuning the defect chemistries of oxide thermoelectrics to improve the figure of merit ZT in these more robust family of oxide ceramics. She has previously worked on piezoelectric and ferroelectric materials as well as the discovery and characterization of new honeycomb-ordered layered oxides with interesting ionic conducting and magnetic properties. She has also been heavily involved in the development of a new ceramics processing and characterization lab course for 2nd year undergraduates in the Materials Science and Engineering department at the UoS. This has incorporated new techniques for the students and improves the alignment of learning between the lecture courses and practical lab experience in the realms of X-ray diffraction, electrical and thermal characterization of ceramic oxides. She employs her teaching experience and broad background to mentor many of the PhD, MSc and UG students in the group.

Displaying Brant_Walkley.jpg
Dr Brant Walkley joined the Department in October 2016, under the SUbST grant, working within the Functional Materials and Devices group. His research is focused on understanding composition-structure-property relationships within electroceramic materials, with a particular focus on materials for thermoelectric applications. He has a wide range of expertise in materials synthesis and characterisation, particularly in regard to application of advanced solid state nuclear magnetic resonance (NMR) spectroscopy to inorganic materials. Prior to joining the Department, Brant completed his PhD in October 2016 within the Department of Chemical and Biomolecular Engineering, The University of Melbourne, Australia, where his research focused on understanding composition-structure-property relationships within geopolymers and low-CO2 cements via application of advanced spectroscopic and microstructural analysis techniques.

Dr Fan Yang joined the Functional Materials and Devices group at the University of Sheffield in November 2014 as a postdoctoral research associate on an EPSRC grant. Her current research focuses on developing new electrolyte and/or electrode materials for intermediate-temperature solid oxide fuel cells. She has a wide range of expertise in materials processing and characterisations, particular in coupling impedance spectroscopy with finite element modelling to study the electrical properties of electroceramics, composites and coatings, as well as understanding the composition-structure-property relationships of fluorite, pyrochlore and perovskite-type oxides. Fan obtained her PhD from University of Manchester, where her research focused on the electrical and thermal properties of zirconia-based ceramic materials. So far Fan has published 27 peer review journal papers reaching total citations of 168 and an h-index of 8.

Recent papers

1) High ionic conductivity with low degradation in A-site Strontium-doped nonstoichiometric Sodium Bismuth Titanate perovskite, Chemistry of Materials, F. Yang, H. Zhang, L. Li, I. M. Reaney and D. C. Sinclair,  28 (2016) 5269-5273

2) Enhanced bulk conductivity of A-site divalent acceptor-doped non-stoichiometric sodium bismuth titanate, F. Yang, P. Wi, D. C. Sinclair, Solid State Ionics, 299 (2017) 38-45.