Thursday 21 December 2017

Cold Sintering Processing - What is it?




PhD Student Sinan Faouri briefly gives us an overview of Cold Sintering Processing, a novel technique for the processing of functional materials that addresses the energy cost of manufacturing these materials.

Sintering is a thermal treatment process of forming a dense bulk solid material by heat or pressure before reaching its melting point [1,3]. The conventional sintering process is a high temperature sintering method where powders are heated between 50-75% of melting temperature to > 95% theoretical density [2]. Heating the starting materials to high temperatures facilitates the motion of atoms, enabling the homogenisation of the bulk solid [5].

Cold sintering processing (CSP) is a novel technique developed recently to achieve dense ceramic solids at extremely low temperatures ( < 180 ℃ ). across a vast variety of elements and composites [3]. The process includes using aqueous-based solutions (eg: water) as transient solvents to aid densification by a non-equilibrium mediated dissolution–precipitation process [4].

In order to provide a good environment and conditions for precipitation and recrystallization in hydrothermal reactions, a convenient aqueous solution should be chosen carefully which will be also significant in reducing sintering temperature [5].

To achieve densified bulk materials, some additional characteristics to the pre-dominance diagrams are used when studying CSP effective factors as shown in figure (1) [5].






    


Figure 1: Flowchart summary of CSP stages



Figure (1) shows a flowchart for the possible roots of CSP from particle rearrangement to densification. The internal characteristics that affect CSP are the material’s composition, crystal structure, particle size and solubility in water [5]. Some of the physical variables determining the kinetic processes for mass transport are the hot press pressure, sintering temperature, time of sintering, the rate of heating, and the atmosphere pressure [5]. Preparing a convenient aqueous solution is also critical as some other significant factors to CSP include the nature of the solute, the concentration of the solute and pH value. The latter can be studied via pre-dominance diagrams [5].

The dissolution nature plays a significant role in determining whether densification will eventually occur or not. If the materials dissolve equally with ease, a direct and simple CSP is possible, since the surface of material can be easily dissolved in water with a homogenous chemical stoichiometry [5]. However, no densification will occur if one material dissolves more easily that the other. This is because one material will form a passive surface [5]. Negligible dissolution can work well in CSP if a saturated solution is added that targets the chemical compounds of the material to be densified [5].

The next steps in CSP are evaporation of the liquid, the hydrothermal crystal growth (in the case of water as a solvent) or formation of a glass/intermediate phase, and eventually grain growth and densification or recrystallization of a glass where it gets ejected as shown in CSP flowchart in figure (1) [5].





References

2.      Dr. Jing Guo, Dr. Hanzheng Guo, Amanda L. Baker, Prof. Michael T. Lanagan, Dr. Elizabeth R. Kupp, Prof. Gary L. Messing, Prof. Clive A. Randall. Cold Sintering: A Paradigm Shift for Processing and Integration of Ceramics. Volume 55, Issue 38 September 12, 2016. Pages 11457–11461
3.      Hanzheng Guo, Jing Guo,  Amanda Baker, and Clive A. Randall. Hydrothermal-Assisted Cold Sintering Process: A New Guidance for Low-Temperature Ceramic Sintering. ACS Appl. Mater. Interfaces 2016, 8, 20909−20915
4.      Jing Guo, Amanda L. Baker, Hanzheng Guo, Michael Lanagan, and Clive A. Randall. Cold Sintering Process: A New Era for Ceramic Packaging and Microwave Device Development.  J. Am. Ceram. Soc., 1–7 (2016)
5.      Hanzheng Guo, Amanda Baker, Jing Guo, and Clive A. Randall. Cold Sintering Process: A Novel Technique for Low-Temperature Ceramic Processing of Ferroelectrics. J. Am. Ceram. Soc., 1–19 (2016)

Friday 3 November 2017

Energy of the Future - Solid Oxide Fuel Cells

FMD PhD student, Julia Ramirez Gonzalez gives us an overview of how Solid Oxide Fuel Cells operate and the importance of such materials in meeting future energy production challenges.

Can you imagine our daily life without electricity? Maybe we can deal with it for a couple of hours, but this commodity has become one of the engines of our generation [1]. Nevertheless, the environmental implications of producing energy by fossil fuel combustion, is the driving force to look for more efficient and environmentally friendly alternatives of electricity generation.

Fuel cells are one of the alternatives. These devices generate electricity by an electrochemical reaction of gaseous reactants. One of the reactants is the oxygen in the air, and the other is hydrogen or a hydrocarbon [2]. The configuration of this devices resembles a sandwich. It has two electrodes, one in contact with fuel (anode), and the other in contact with oxygen (cathode): These two interfaces are separated by and electrolyte. There are many types of fuel cells, which are classified by its type of electrolyte, such as polymer electrolyte membrane (PEM), alkaline (AFC), phosphoric acid (PAFC), molten carbonate (MCFC), and solid oxide (SOFC) [3]. Each type differs in its operation temperatures, useful fuel, efficiency and therefore its applications.

Research on SOFC showed that these materials can work with higher hydrocarbons, giving them the advantage of fuel flexibility. And the most important feature is that all of its components are solid, which avoids the risk of spillages, gives it the freedom for stacking configuration, and it is a quiet system as it does not have any moving parts [2][4] . 

But how does it work? On one side of the cell there is a high concentration of oxygen and on the other side there is none. An electrical potential gradient across the electrolyte is built up. However, the electrolyte does not allow electrons or gas to flow through, but its crystal structure has oxygen vacancies, which allows the migration of oxygen ions. Therefore, at the three-phase boundary, cathode-electrolyte-air, oxygen will be reduced, by obtaining electrons from the cathode [2], Equation 1. 




Eq. 1
Thus, oxygen ions can hop through the electrolyte and can reach the anode-electrolyte-fuel boundary, where the fuel oxidizes; where the products will be steam and electrons, Equation 2 [2].




Eq. 2


If the anode and cathode are connected by an external circuit, the cycle is repeat again as long as the two gases are present, and this is how electricity can be harvested through the external circuit. As shown in the video. 







These devices operate in the temperature range between 500-1000°C, which adds challenges to the material requirements. The materials need to have chemical stability, to avoid reaction with the reactants, a similar thermal expansion coefficient, to reduce the possibility of cracks during cycling; strength and toughness, no one likes a broken device; but also, it has to be easy to fabricate and have a low cost [4].

As you can see there are many requirements, but material scientists like these challenges and have come up with several options.

Yttria-stabilised zirconia is the most widely used as an electrolyte, which is zirconia doped with yttria (Zr1-xYxO2-x/2; x: 0.08). It can also be doped with calcium oxide, magnesium oxide, scandium oxide, neodymium oxide and ytterbium oxide. In addition, cerium oxide doped with samarium (SDC), gadolinium (GDC), and calcium (CDC); lanthanum gallate; bismuth yttrium oxide; barium cerate and strontium cerate, can be also used. The reason of the high operation temperatures of these devices is to promote the oxide ion conduction within the electrolyte [4].

Both electrodes have to be able to distribute the hydrogen and oxygen respectively, serve as catalysts and allow the flow of electrons. Therefore, the anode is a porous ceramic-metallic composite. The metal provides the electronic conduction pathway for the electrons, the ceramic made from the same material as the electrolyte assures a similar thermal expansion coefficient and good compatibility. The popular choice is Ni-YSZ, but there is also Ni-SDC and Ni-GDC [4]. 

For the cathode also a porous structure to allow the flow of gas usually made from a perovskite-type lanthanum strontium manganite (LSM), and lanthanum calcium manganite (LCM); also provides a similar thermal expansion. It is been discovered that by making a composite of perovskite and electrolyte increases the active sites for the electrochemical reactions [4]. 

These electricity generation systems have many possibilities and applications. It can be used as a combined heat and power plant, distributed generation, but also used in remote areas as the generation can be at the point of consumption, reducing the transmission costs. It has an efficiency of ~60% [3]. From an environmental point of view the CO2 emissions will be considerable reduced, Mike Manson an expert in SOFC from Manchester said to The Guardian that a 35% reduction in CO2 emission could be possible using this technology, comparing it with consuming electricity from gas power plant and hot water from a boiler [5]. There is also the idea of a hybrid/gas turbine cycle, to take advantage of the high temperatures of the existing power plants [3]. There are many companies that see the potential of this technology and have and R&D area dedicated to it, as Rolls-Royce and Bloomenergy [6][7]. 

In summary, SOFC are a great alternative for the generation of electricity, further research needs to be done to reduce its operations temperatures, but it represents a step closer to a greener electricity technology era.

[1]          “Key world energy statistics,” Int. Energy Agency, 2017.
[2]          R. J. Kee, H. Zhu, and D. G. Goodwin, “Solid-oxide fuel cells with hydrocarbon fuels,” Proc. Combust. Inst., vol. 30, pp. 2379–2404, 2005.
[3]          D. of Energy, “Comparison of Fuel Cell Technologies | Department of Energy.” [Online]. Available: https://energy.gov/eere/fuelcells/comparison-fuel-cell-technologies. [Accessed: 01-Nov-2017].
[4]          A. B. Stambouli and E. Traversa, “Solid oxide fuel cells (SOFCs): a review of an environmentally clean and efficient source of energy,” Renew. Sustain. Energy Rev., vol. 6, pp. 433–455, 2002.
[5]          D. Clark, “Manchester Report: Ceramic fuel cells | Environment | The Guardian,” The Guardian, 2009. [Online]. Available: https://www.theguardian.com/environment/2009/jul/13/manchester-report-fuel-cells. [Accessed: 30-Oct-2017].
[6]          Rolls-Royce, “Rolls-Royce grows global fuel cells capability with US acquisition – Rolls-Royce.” [Online]. Available: http://www.rolls-royce.com/media/press-releases/yr-2007/rr-grows-global-fuel-cells.aspx. [Accessed: 02-Nov-2017].
[7]          Bloomenergy, “Fuel Cell Energy - Solid Oxide Fuel Cells SOFC | Bloom Energy.” [Online]. Available: http://www.bloomenergy.com/fuel-cell/solid-oxide/. [Accessed: 02-Nov-2017].



Friday 6 October 2017

Sustainability of Operation Research and Management

Lucy receiving her award from the Conference Chairs,
Prof. Ying Fan and Prof. Ernesto DR Santibanez.
The Second Global Conference on The Applications of Operations Research and Operations Management for Sustainability (GCTAOS) was held from the 6th to the 8th September at Beihang University in Beijing, China.

Lucy Smith was able to attend after receiving the Research Student’s Travel Grant from the Worshipful Company of Armourers and Brasiers and present research on the life cycle assessments of high and intermediate temperature Solid Oxide Fuel Cell material structures. In addition to this, the Advance Resource Efficiency Centre, led by Prof. Lenny Koh, were able to showcase the SCEnATi (Supply Chain Environment Analysis Tool) to an international audience.

A wide range of key note speakers gave their thoughts on issues such as smart systems, relief chain management, energy investment and technology evaluation. This paved the way for an interesting collection of presentations on similar topics from other academics.

The conference was attended by academics, student and industry representatives allowing for interesting discussion and future collaboration opportunities.

Lucy was awarded the Best Paper Award, in recognition of the professional excellence of the paper for ‘Life cycle assessments and environmental profile evaluations of high and intermediate solid oxide fuel cells’ by L. Smith, F. Yang, T. Ibn. Mohammed, I. M. Reaney, D. C. Sinclair and S. C. L. Koh.


Monday 11 September 2017

11th EUCO-TCC - Barcelona

11th European Conference on Theoretical and Computational Chemistry 3rd-7th of September, Barcelona, Spain

The central courtyard of the institute bathed in the glorious Barcelona sun.
Hosted at the Institute for Catalan Studies (IEC), in Barcelona, a majestic building built in the 17th century, the IEC, along with EuCheMS (European Chemical Services), hosted the 11th European Conference on Theoretical and Computational Chemistry.

As a computational chemist working in material science this was the perfect opportunity to network with a diverse group of researchers, who all share the same interest in simulating chemistry at the atomic level. Topics included solvation, catalysis, biochemical reactions, and material science. Given the nature of the conference there was also a focus on the techniques being developed to simulate these systems, such as density functional theory, molecular dynamics, and machine learning.

Highlights for myself included the work by Matti Hellstroem, from Georg-August-Universitat Goettingen, who works for Jorg Behler. Matti presented recent work on simulations of water and sodium hydroxide using the Behler type neural network potentials. The simulations represent how mature these methods are, though also demonstrate that there are still some hurdles to overcome. Mattis’ demonstration of the process of proton transfer through the system, and the importance of the types of clusters that form locally about sodium to enable the making and breaking of bonds.

The SnIP double helix structure
Tom Nilges from the Technical University of Munich, presented his work on the curious inorganic double helix SnIP semiconductor that have potential as a functional material. The double helices consist of  twisted chains of tin iodide (SnI+) intertwined phosphide (P–) chain. The band gap of the material, and mechanical strength, lends itself well to potential solar cell applications, and the next steps are exploring the analogues of the material.

The keynote lecture, and EuChemMS award winner, Ursula Roethlisberger, from Ecole Polytechnique Federale de Lausannae, Institut des Sciences det Ingenierie Chimiques, presented her novel work combining machine learning and computational chemistry. Primarily her work utilises DFT calculations to generate high quality, and well sampled training data, that can then lead to quick hits for discovering molecules with ideal properties. I also took the time to chat to her regarding her work on simulating MALI and related photovoltaic materials, and how she is using machine learning to search the structure space of these materials.

Overall the conference was an excellent opportunity to connect with fellow computational chemists, some who are familiar faces, and to present the research from the SUbST group to a wider audience.

Tuesday 1 August 2017

Next Generation Force Fields - Designing force fields in an age of cheap computing - Perspective


This past week at Halifax Hall, the University of Sheffield was host to a workshop of experts and world leaders on computational chemical simulations. The aim of the workshop was to present the advances in this field, for the atomistic simulation of bulk materials, surfaces, interfaces, solutions, biomolecules, and more. It was also a chance for the delegates to discuss the next challenges facing the discipline given the increasing power of computers.

Chaired by Dr Colin Freeman, Dr Chris Handley, and Prof. John Harding, the invited speakers included Prof. Nohad Gresh, Prof. Jorg Behler, Prof. Bernd Hartke, Prof. Stefan Goedecker, Dr Peter Brommer, Prof. Paul Popelier, Dr Paul Richmond, and Dr David Mobley.

From the talks and contributions it was clear there are common challenges that all researchers face in the coming years. In terms of the technologies available, the push to GPU computing, driven by machine learning, means that the software used for chemical simulations must be reassessed if they are going to exploit the potential computer power on offer.

Another key issue is how machine learning is used to design new chemical simulations. Machine learning, such as neural networks, or Gaussian process regression, can be trained to extract the underlying non-linear relationship between atomic positions and some property of the system (we are often looking for the relative energy differences for a given configuration of atoms, and the associated forces as these are used to drive the molecular dynamics simulation). The machine learning methods use for training data quantum mechanical simulations. The danger however, is that while the non-linear model is discovered, we retain no information about the true physics at play, which is critical if we wish to have a deeper understanding of the interactions at play within a simulation.

Physics driven models are the alternative, but these models rely on knowing the proper functional forms for describing the interactions between atoms. Classical force fields often use functional forms that have been used over the decades that were initially chosen for computational convenience. Going forward our choice of functional forms used should be reassessed given that computational power is no longer an issue.
The effect of d-electrons on atomic configurations is an
electronic orbital effect and one that is not captured in
traditional force fields.


Related to the two previous points, is one of transferability. Force fields are often fitted, and thus simulate well, a particular chemical system in certain conditions. Knowing the limits of a particular model, and also how badly it will perform when if such conditions are met, is knowledge not often provided when a force field is published. Care must be taken that a model is capable of representing all the relevant physics that describes the system. There may be underlying physics not accounted for by the model explicitly, which hinders the transferability of the model when applied to similar chemical systems.

Transferability, data driven models, and physical driven models, ultimately are tied to how we partition the energy of a force field. By this we mean, how do we cut up the force field into different interactions, and how we even define these interactions. How do we define bonds? Can we accommodate reactivity into our models? What of electrostatic interactions? Should we use multipolar descriptions of charge?

Fitting and automation can be reliant on "wizardry". By that we mean, "to use a force field, and to design derivatives of it, how much highly specific expertise do we require - is the force field only really usable by those who designed it?" This is not ideal, as this slows the development of new models, and also hinders insight into why models work and fail for particular simulations.

Finally there is the topic of the reference data. More often than not, force fields are fitted to quantum mechanically generated reference data. We assume that this data is the "truth". Though, while many of the programs that perform quantum mechanical calculations have over time become closer in agreement with each other, they all share the same issue of accuracy. The fitting of force fields is thus a cyclic issue, where a reassessment of the training should be performed periodically.

Going forward the issues raised during the workshop will help inform CECAM and EU funding on future force field development and how it plays a critical role in computational chemistry, even in an age of high performance computing.

As organisers of the workshop, Colin, Chris and John would like to thank CECAM and CCP5 for the generous funding for the event, the invited speakers for their informative presentations, and the attendees whom we hope will have taken away new ideas and new future collaborations.



Conference Attendees

Wednesday 12 July 2017

Advanced Resource Efficiency Centre (AREC) Showcase in the European Parliament




On 27th June 2017, the AREC team, led by Professor Lenny Koh, showcased its research and impact at the ‘Pathways to Global Policy, Industry and Societal Impact on Resource Efficiency and Sustainability’ event at the European Parliament, Brussels.

The event was hosted by John Procter, MEP for Yorkshire and Humber, through the White Rose Brussels group (https://brussels.whiterose.ac.uk/) and attended by policy makers, industry representatives and academics. The main aims of the event were to present the impact of AREC’s research and develop potential future connections to further extend AREC’s impact reach.


The event included a panel discussion from Professor Lenny Koh, Professor Panos Ketikidis (Vice Principal: Research and Innovation, International Faculty of the University of Sheffield in Thessaloniki, Greece), Jay Sterling Gregg (European Energy Research Alliance, representing “e3s”, Brussels, Belgium), Philippe Micheaux Naudet (Association of Cities and Regions for Sustainable Resource Management – ACR, Brussels, Belgium) and Maria Rincon-Lievana (Policy Officer – Circular Economy Action Plan, DG Environment, Brussels Belgium).

Professor Koh presented the SCEnATi (Supply Chain Environmental Analysis) tool to the group of industry specialists and academics. The SCEnATi tool is used within the FMD group to produce comparative hybrid life cycle assessments of functional materials and devices.

Professor Koh commented “Being resource efficient and sustainable should be embedded as a new norm in every supply chain, every business and every organisation whether these are public, private or third sectors. Policies that support this goal, industry practices that promote such implementation, technologies/tools that enable this achievement, and research and innovation that underpin the delivery of this new norm would lead to positive societal, economic and environmental impact”.


For further information on the SCEnATi tool please contact: Lucy Smith, lsmith17@sheffield.ac.uk

Thursday 6 July 2017

Full Tilt - Why it Matters in Matter

"Tilting" in perovskites is all about the subtle arrangements of atoms in materials, which is inherently related to the properties of materials, such as capacitors and piezoelectrics. Tilt is also something we can control, by doping a material with another type of atom. By controlling tilt, we can design novel materials.

http://www.nature.com/nphoton/journal/v8/n7/full/nphoton.2014.134.html
I am not a materials scientist by training, but a computational chemist with a background in simulations of water, peptides, and using machine learning. So I don't think of atomic structures are rigid arrangements of atoms, but being dynamic. So I see perovskites not as neat octahedral units of B site atoms surrounded by oxygen atoms (or whatever the X site atom happens to be). In reality these octahedral units are irregular, and fluctuating, especially at ambient conditions and when heated. But if you only consider X-ray diffraction determined crystal structures, you may be led into thinking the opposite.

So what do we mean by "tilt"?

Tilt means that the octahedral units that we have defined, are aligned in a manner that means the octahedral units either do, or do not, superimpose upon their neighbours. This tilt is classically defined by Glazer (using a frustrating description of rotation if you prefer Euler angles!), and from which we get different crystal structure classifications that differ by the manner the octahedral units tilt and overlap.

In the material calcium titanate, all the A site atoms are barium, the B site titanium, and X sites are oxygen. At high temperatures calcium titanate exhibits no tilt. It's cubic. But when we start to dope the material on the A site, with larger or smaller ions, such as barium, we begin to distort the structure. Or if we cool the material down, tilting emerges.



AA3B4X12 perovskite structure showing the octahedral environment of the B cation
http://pubs.rsc.org/en/Content/ArticleHtml/2010/JM/b926757c

Distorting the material has a knock on effect on the ions in the material. The titanium now no longer sits in an isotropic (so a fully symmetric and even) electrostatic field created by the oxygen atoms about it. This means the titanium atoms get shifted. The same happens with the calcium ions too.

It's this combination of distortion that generates a dipole moment - a displacement of electrostatic charge in a particular direction within the crystal structure.

So what is the challenge in materials science?

Exploring how we can dope materials, and manipulate this tilting, in a targeted manner, relies on experiment and theory working in tandem. X-ray diffraction defined structures do not show the oscillations but use structure factors to account for thermal scattering that induces oscillations of the atomic positions. From Transmission Electron Microscopy (TEM) we can generate diffraction patterns which can show this oscillation of structure. And from theory, via simulations of atoms via Molecular Dynamics, we can assess the degree of tilting (not defined by Glazer), and begin to predict TEM diffraction patterns.

The hope then is that a combination of techniques, both experimental and theoretical, can reveal further insight into the complex relationship of atomic structure and materials properties.


 Atomic resolution image of 2D halide perovskite CsPbBr 3 . (a) Structure model of cubic CsPbBr 3 perovskite unit cell. Cs (green) occupies the corner A-site while Pb (gray) occupies the body-center Bsite , and Br (brown) occupies the face-center. Pb−Br 6 octahedron is formed within the Cs cube framework. (b) Structure model of single layer 2D CsPbBr 3 NS. (c) Atomically resolved phase image of a 2D CsPbBr 3 NS obtained by reconstructing 80 low dose-rate AC-HRTEM images via exit-wave reconstruction. The [001] structure projection of a unit cell is overlaid on the image.
http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b03331  








Wednesday 7 June 2017

Functional Materials for a Sustainable Future

Last month, on the 15th of May, the University of Sheffield Functional Materials and Devices group hosted a workshop centred on the topic of "Functional Materials for a Sustainable Future". A diverse number of speakers from out own group, and collaborators, and industrial partners, gave insightful and exciting talks on how a range of materials can be designed and fabricated, for use in a wide range of applications.

Presentations ranged from magnetic materials for cooling, solar power materials, and the use of computational simulations to model novel materials. The workshop was also an opportunity for the FMD group to demonstrate the value of KTP (Knowledge Transfer Partnerships) whereby researchers can pursue underpinning research to enable novel materials discovery and applications.

Guests included representatives from QinetiQ, Johnson Matthey, CeramTec, Rolls-Royce, and more (a full list can be found on the event page).

























Functional materials in Japan

The assembled attendees
Between the 29th and 31st of May, the 8th International Conference on Electroceramics (ICE) was held at Nagoya University in Japan.

Topics covered at the conference encompassed most of the oxide functionalities, including piezoelectrics, thermoelectrics and ferroelectrics. Plenary lectures included Prof John Kilner (Imperial), Prof Harry Tuller (MIT), and Dr Nava Setter (EPFL).

Attendees included academics, students and industry representatives, which enabled some interesting discussions about the future directions of functional materials.  

Becky receiving her prize
Becky attended as a speaker, talking about her work on control of morphology in barium titanate, for which she won a Young Presentation Prize.

There was also a moving memorial symposium for the late Prof Eric Cross (PSU) a pioneer in the ferroelectrics field, who passed away at the end of 2016, with contributions from former students and colleagues.

Wednesday 10 May 2017

Invited lecture at Manchester University on perovskite solar cells


On May 3rd 2017, Dr Giorgio Schileo was invited to give a lecture on the state-of-the-art and industrial applications of perovskite solar cells to Renewable Energy MSc students at the University of Manchester.

The talk covered the physical chemistry aspects of perovskite solar cells, including insights on the challenges that a new technology must face to make the transition from academic novelty to useful product that generates a profit. Perovskite solar cells are a good example of this process, as they generated an enormous amount of interest in the academic community and attracted considerable investments worldwide, even though critical issues (stability, toxicity of Pb, etc.) still have to be addressed.

Dr Schileo also presented the KTP scheme to the students as a possible route to secure a job in the industry while gaining some additional skills, and also different aspects such as market shares, overall cost considerations, and scale-up issues.


Monday 10 April 2017

1st Annual ICON Conference, Athens

On April 7th 2017, Becky was an invited speaker at the International Consortium of Nanotechnology's (ICON) 1st Annual Conference. This Consortium provides funding for a global network of PhD students working in a wide variety of nanotechnology fields such as graphene and perovskite solar cells. ICON is an initiative funded by the Lloyd's Register Foundation (LRF), who also supports Becky's fellowship. The LRF are a charity committed to improving the safety standards in engineering across the globe, and to promote scientific education, with ICON being one of their flagship schemes.    




The conference was a mix of fascinating talks about ICON, the LRF, and presentations from the PhD students themselves each of whom had three minutes to explain their work. Each speaker rose to the challenge and it was a great introduction to their work and to the later poster session. 

Becky's talk was about where a career in nanoscience could lead, by drawing on her experiences as both a PhD and PDRA. Following on from the experiences of an LRF-funded PhD student coming to the end of her work, Becky gave a brief introduction to her work and a few hints for the assembled PhD students on getting the most out of their PhDs.

The conference was held in central Athens, Greece, and provided the delegates with the opportunity to explore the wonderful historical sites in the city, including the fantastic conference dinner which was held at the Acropolis Museum, with views of Acropolis Hill and the Parthenon

Friday 7 April 2017

From Bits to Batteries - Cafe Scientifique Post-Mortem

On Monday, April 3rd, FMD group member, Dr Chris Handley, gave his talk, "From Bits to Batteries", to a public audience thanks to the local Café Scientifique organisation. Café Scientifique is place for academics and researchers to present their work to a public audience, consisting largely of non-experts. Outreach opportunities such as these are an ideal way to demonstrate the value of academic research, and the value of investment into research.


Douglas Bell, who helps organise the Sheffield Café Scientifique events was able to attend,


"Christopher explained the chemistry and the computation approaches clearly. He displayed both in-depth knowledge and enormous enthusiasm for the topics. Visuals were rich in useful diagrams and animations. He handled questions sensitively and helpfully.

The talk was pitched just right for an audience with limited science background. It was well received and fitted well within the programme of Café Scientifique."

Chris' talk demonstrated the importance of computational simulations as a underpinning research tool for materials design and discovery, and generated some excellent discussion, with audience members eager to further understand the future implications of machine learning in the field, and further examples of how simulation and experiment works in tandem within the FMD group.

In the future we hope to present more of our work at these public gatherings, and perhaps have PhD students give shorter presentations as a group.

Wednesday 29 March 2017

From Bits to Batteries - Cafe Scientifique preview


On April 3rd 2017, the Sheffield branch of Cafe Scientifique will be be hosting FMD member, Dr Chris Handley, as he presents his talk, "From Bits to Batteries".

Cafe Scientifique is place for academics and researchers to present their work to a public audience, consisting largely of non-experts. Outreach opportunities such as these are an ideal way to demonstrate the value of academic research, and the value of investment into research.

For the FMD group, and Chris in particular, this is a chance to show the public how we are searching for novel functional materials, and what uses we are designing these materials for. Furthermore, it is a chance for Chris to show the importance of underpinning fundamental research in understanding how the chemistry of these materials, through the use of simulations, influences the properties of these materials, and so allow us to design and discover, novel materials.

In his talk, Chris will use a couple of case studies from his own research to demonstrate who we design models to simulate chemistry and thus materials, and his vision for future methods for simulating materials.

Chris' talk will take place at 7pm, the 3rd of April, 2017, at the Showroom Cafe Bar in Sheffield.


Tuesday 21 March 2017

Functional materials in Parliament


On March the 15th 2017 Becky attended Voice of the Future 2017 at Portcullis House in Westminster. The event saw participants from a range of organisations invited to submit questions to a range of science Ministers and Government advisers about the future of science policy in the UK, and to hear their answers and thoughts on this important topic. Becky was there on behalf of the Royal Academy of Engineering, and had submitted questions ahead of time to be asked on the day.

First under the spotlight was the Shadow Minister for Industrial Strategy Secretary Chi Onwurah. Of the questions asked, her stance on the lack of taboo which makes it acceptable to be bad at maths was particularly interesting, although the question of how to solve this issue, particularly amongst school-age girls, was left open.

Next was Sir Mark Walport, chief scientific adviser to the Government, closely followed by Jo Johnson, Minister who gave the party line on the likely effects of the UK’s exit from the EU. He gave a very interesting account of the party line, with an overall positive outlook, even with the uncertain times faced by scientists and the UK in general.

Finally, questions were put to four members of the Science and Technology Select Committee. This was particularly interesting as these are the MPs who write reports to directly advise the Government in their decision-making.


Overall, the day was a fascinating insight into the inner workings of science policy in the UK, and a great opportunity to visit the House of Commons, even if, having seen the questions ahead of time, the answers sometimes felt a little prepared. More information about the event can be found here and a recording of the afternoon can be found on the Commons website

Tuesday 7 March 2017

Event - Functional Materials for a Sustainable Future

May 15th 2017, at the University of Sheffield, the FMD group will be hosting a workshop on "Functional Materials for a Sustainable Future". The workshop will feature talks focusing on electroceramic materials, and identifying the future challenges facing the industry.

Talks will be given by both university academics and guests from leading industrial partners, such as Dyesol, Isotek, and Johnson Matthey.

Monday 20 February 2017

Thermoelectric Network UK Meeting



Adindu presenting his poster
On the 14th and 15th February 2017, thermoelectrics researchers from the UK, Europe and Japan gathered in Manchester, UK for the spring EPSRC Thermoelectric Network UK Meeting. The programme encompassed the full range of thermoelectrics research, from fundamental materials studies, to updates from industries already using this technology. Prof Derek Sinclair was an invited speaker, and gave an overview of the different thermoelectric research strands here at Sheffield. He was joined at the meeting by Lloyd’s Register Foundation/Royal Academy of Engineering Fellow Rebecca Boston, research associates Whitney Schmidt and Brant Walkley, and PhD student Adindu Iyasara, who presented a poster on his doped strontium titanate research.

Although this was the final Thermoelectrics Network UK meeting, it is hoped that the strong links which have been created between the various global groups will be maintained in the future.    

Friday 3 February 2017

CECAM Workshop - Designing Forcefields in an Age of Cheap Computing July 26, 2017 - July 28, 2017

FMD researchers Prof John Harding, Dr Colin Freeman and Dr Chris Handley recently won funding to host a workshop at the University of Sheffield, the topic being "Designing Forcefields in an Age of Cheap Computing"July 26, 2017 - July 28, 2017.

Robust, reliable forcefields are central to successful atomistic simulations. This workshop will bring together leading experts to discuss the impact of increasing computer power, both in terms of speed and data storage, on the development, validation and use of forcefields in molecular simulation.

Chris: As a researcher who has worked in the field of chemical simulation since my master project with Prof Paul Popelier, it is exciting to be able to host a workshop such as this, bringing together experts in atomistic simulations for all manner of materials and molecules, and to discuss the problems that still persist in traditional simulation methods, and how they might be addressed with cutting edge computing techniques. It should lead to lively discussions and some good insight into how such simulations can take advantage of modern computing power.

Invited speakers will also include experts in machine learning and GPU programming, who can give an informed perspective on modern HPC computing.

The workshop by its nature with feature keynote presentations, framing particular topics in chemical and materials simulations, with more open discussion forums between talks, allow groups to break off and tackle topics in more depth.

Short talks and posters are welcome.


Delegates will be hosted at Halifax Hall, located on the west side of Sheffield City Centre and only a short walk from Ecclesall Road, an area which provides a hub of bars, pubs and restaurants. It offers a great location for both business and leisure trips in Sheffield. Situated within The University of Sheffield’s Endcliffe student village it also offers the perfect place for visiting parents and prospective students to stay.

Local attractions include the picturesque Botanical Gardens, only five minutes away, whilst shopping and other city centre attractions are easily commutable by bus and taxi. Further afield the location offers great access to The Peak District National Park, which by car is only a 15 minute drive, whilst the stunning Chatsworth House is only a 30 minutes’ drive.



ICACC - International Conference and Expo on Advanced Ceramics and Composites

The 41st InternationalConference and Expo on Advanced Ceramics and Composites (ICACC) was held on 22-27 January 2017 at Daytona Beach, Florida, USA. This annual conference showcases cutting-edge research in advanced ceramics, armour ceramics, solid oxide fuel cells, ceramic coatings, bio-ceramics and more. Postdoctoral Research Associate Dr. Fan Yang from our group attended the conference and presented our recent work on tuning the electrical properties of sodium bismuth titanate perovskite by chemical doping with a focus on the oxide-ion conduction behaviour of NBT. Her presentation has raised lots of attention from the audience who also work on developing new electrolyte/electrode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs).


Some key invited speakers working on oxide-ion/mixed conductors include Professor Eric Wachsman from University of Maryland, USA, Professor Tatsumi Ishihara from Kyushu University, Japan and Professor Scott Barnett from Northwestern University, USA. Other symposiums related to our group’s work include lithium/sodium ion batteries, thermoelectrics and piezoelectrics, etc.

Hilton Daytona Beach Resort where the conference 
was held and the beautiful sea view outside Hilton



Friday 20 January 2017

FMD group’s expertise highlighted in new Chemistry of Materials review


The ceramic processing and thermoelectric characterisation expertise in the FMD group has been recently highlighted in an invited review in Chemistry of Materials. The paper, part of a major special edition of the journal, covered the major aspects of lab-based ceramic processing, and the standards required for reliable thermoelectric measurements, and gives a step-by-step guide to making high quality, reproducible ceramics using solid state processing. It also covers the major techniques and potential pitfalls associated with the characterisation of thermoelectric properties in n-type ceramics.

January’s special edition comprises a series of articles from internationally recognised groups, containing protocols and “trade secrets” in a wide variety of research areas, direct from the researchers in the field, and we were very pleased to be included in this wide ranging edition. 


The full reference is as follows: 

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

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


Friday 13 January 2017

N8HPC/CCP5 New Approaches to Atomistic and Quantum Simulation of Materials

Dr David Quigley from the University of Warwick introduces Robyn.
On Friday 6th of January, a couple of us were at the New Approaches to Atomistic and Quantum Simulation of Materials; N8HPC and CCP5 Network Event in York, UK. This one day event brought together computational chemists, solid state materials scientists and more, from the N8 group of universities, plus guests from further afield.

PhD student, Robyn Ward presented her work on the application of metadynamics to explore the migration pathways of ions in BaTiO3. The novelty of her work helps further the understanding of just how the materials work that are made in our ceramic laboratories.


The 5x5x5 supercell of MALI, quenched from 400K to 50K.
Grey lead iodide octahedra show tilting.
Methylammonium ions show ordering in their
alignment not present at room temperatures
Research fellow, Dr Chris Handley also attended, presenting his recently published work on developing a forcefield for Methylammonium Lead Iodide, again another material that is being synthesised within our experimental laboratories.

The event was a great chance to network with those with whom we can share expertise with, and to talk in person with the developers of particular simulation programs. This is particularly useful as we branch out to running new types of simulations and deepening the synergy between our computational and our experimental materials scientists.

Some particular highlights from other speakers at the event was Dr David Quigley from the University of Warwick (where Chris used to work) presenting his work on simulations of Ice 0, and the work of Prof Gabor Csanyi from the University of Cambridge and his machine learning based simulations for materials.