tuesday 22 september 2020...tuesday 22nd september 2020 10:00 - 10:15 welcome session 1 chair:...
TRANSCRIPT
Tuesday 22nd September 202010:00 - 10:15 Welcome
Session 1Chair: Struan
Simpson
10:15 - 10:45 Invited Speaker: Dr Lucy Clark, University of Birmingham, UK10:45 - 11:00 Otto Mustonen (Sheffield University, UK)
Non-magnetic cations can drive magnetic interactions in double perovskites
11:00 - 11:15 Gaynor Lawrence (University of Aberdeen, UK)A Nuclear and Magnetic Structure Study of the Oxypnictide Sr2Mn2.23Cr0.77As2O
11:15 - 11:30 Nicola Kelly (Cambridge University, UK)Structural and magnetic properties of hexagonal Ba3Tb(BO3)3
11:30 - 11:45 Alasdair Bradford (University of St. Andrews, UK)Chemically Tailorable Frustrated Systems: Structural Parity and Disparity in Relat-ed AM(C2O4)0.5F2 (AM = NH4
+, Co2+, Cs+, Mn2+)
11:45 - 12:00 Break
Session 2Chair:
Nathalie Fernando
12:00 - 12:30 Invited Speaker: Dr Eve Wildman, University of Aberdeen, UK12:30 - 12:45 Hanna Boström (Uppsala Universitet, Sweden)
Spin crossover in the Prussian blue analogue FePt(CN)6 induced by pressure or X-ray irradiation
12:45 - 13:00 James Fraser (University of Glasgow, UK)Controlling the Growth of Metallic and Semiconducting 2D-Chalcogenide by Chem-ical Vapour Deposition
13:00 - 13:15 Andrei Novitskii (National University of Science and Technology MISIS, Russia)Reactive spark plasma sintering of BiCuSeO oxyselenides: challenges, phase forma-tion mechanism and related thermoelectric properties
13:15 - 13:45 Lunch
Session 3Chair:Elanor Murray
13:45 - 14:15 Invited Speaker: Dr Paul Sharp, University of Liverpool, UK14:15 - 14:30 Luisa Herring Rodriguez (University College London, UK)
Understanding the Surface Chemistry in Tin Dioxide Gas Senors
14:30 - 14:45 Yong-Seok Choi (University College London, UK)Computational investigation on the effect of hydrogenation treatment on Na2Ti3O7 anode for enhanced Na-ion storage
14:45 - 15:00 Seán Kavanagh (University College London, UK)Bandgap Lowering in Lead-Free Cs2Ag(SbxBi1-x)Br6 Double Perovskite Alloys
15:00 - 15:15 Kieran Spooner (University College London, UK)Optimising Transparent Conducting Oxides for Thermoelectric Applications
15:15 - 15:30 Break
Session 4Chair:
Dr Jason McNulty
15:30 - 16:00 Invited Speaker: Dr Anna Regoutz, UCL, UK16:00 - 16:15 Grant Howieson (University of St. Andrews, UK)
Incommensurate-commensurate transition in the geometric ferroelectric LaTaO4
16:15 - 16:30 Magdalena Cichocka (Stockholm University, Sweden)Deciphering the structure of complex nanocrystalline materials fromTEM and XRPD
16:30 - 16:45 Kent Griffith (Northwestern University, USA)High-rate Lithium-Ion Batteries with Complex Mixed Metal Oxide Anodes
16:45 - 17:00 Susan Cooper (University of Copenhagen, Denmark)Elucidating Nanoscale Structure of Spinel Iron Oxide Nanocrystals Using Pair Dis-tribution Function Analysis of Total X-ray Scattering Data: Influence of Nanocrystal Structure on Growth
17:00 - 18:00 Social - breakout rooms - wine & cheese
Wednesday 23rd September 202010:00 - 10:15 Welcome
Session 5Chair:
Wilgner Silva
10:15 - 10:45 Invited Speaker: Dr Ulderico Ullissi, Nissan Motor Co., Ltd. UK
10:45 - 11:00 Arthur Youd (University College London, UK)Computational investigation of earth abundant electrolytes of the M3AlP2 (M = Li, Na) system
11:00 - 11:15 Ashok Menon (Uppsala Universitet, Sweden)Synthetic Pathway Determines the Non-equilibrium Crystallography of Li- and Mn-rich Layered Oxides
11:15 - 11:30 Laura Driscoll (University of Birmingham, UK)Tunability of sodium-metal-sulfate frameworks for applications in Na-ion batteries
11:30 - 11:45 Break
Session 6Chair: Lizzie
Driscoll
11:45 - 12:00 Sacha Fop (University of Aberdeen, UK)Ionic conduction in disordered hexagonal perovskite derivatives
12:00 - 12:15 Hande Alptekin (Imperial College London, UK)Influence of Structural Changes on Sodium Storage Mechanism and Electrochemi-cal Performance in Hard Carbons for Sodium ion Batteries
12:15 - 12:30 Madeleine Georgopoulou (ILL, France)Zn2-averievite: a new quantum spin liquid candidate
12:30 - 12:45 Emily Luke (University of Bristol, UK)Engineering nanowires of high-temperature superconductors
12:45 - 13:15 Lunch
Session 7Chair: Dylan Tawse
Outreach panelChair:
Dr Pooja Goddard
13:15 - 13:45 Invited Speaker: Dr Pooja Goddard, Loughborough University, UK
13:45 - 13:55 Sophia Constantinou (University of Edinburgh, UK)‘Baking a Battery’ - an educational resource to explain battery manufacturing
13:55 - 14:05 Annie Regan (Trinity College Dublin, Ireland)NanoWOW: Materials Science for Kids
14:05 - 14:15 Emily Hanover (University of Birmingham, UK)Development of new battery education resources for use in schools;Explaining battery recycling methods and use of LiFePO4 as an electrode material
14:15 - 14:30 Outreach Q&A Panel
(Final Judging Decisions)14:30 Prize Winners Announced + Closing
Organising CommitteeElizabeth (Lizzie) Driscoll, University of Birmingham, UK
Nathalie Fernando, University College London, UK
Wilgner Silva, University of Warwick, UK
Dr Jason McNulty, University of St. Andrews, UK
Elanor Murray, University of Birmingham, UK
Kieran O’Regan, University of Birmingham, UK
Struan Simpson, University of Aberdeen, UK
Dylan Tawse, University of Aberdeen, UK
I am a final year PhD student in Prof. Peter Slater’s group working towards novel electrode materials for Li-/Na-ion batteries. I am the current student committee
member of the RSC Solid State Chem group and I am excited, with the rest of this amazing committee, to bring this part of the community together.
I am a second year PhD student at UCL with the Advanced Characterisation of Materials CDT. My research focuses on understanding the X-ray induced damage to a family of organometallic catalysts by way of X-ray diffraction and X-ray photoelectron spectroscopy studies.
I am a third year computational chemist, in Dr Mark Read’s group, looking at the ageing of PuO2 as part of the TRANSCEND consortium.
I am currently a PDRA in the Lightfoot group at the University of St Andrews studying hybrid inorganic-organic tin iodide perovskites. I completed my PhD
with Dr Finlay Morrison (University of St Andrews) studying structure-property relationships in tungsten bronze oxides.
I am a third year PhD student under Profs. Richard Walton and Emma Kendrick supervision. My research focuses on developing and studying the properties of novel disordered rock-salt materials for Li-ion batteries.
I am a third year Faraday PhD student in Prof. Emma Kendrick’s group.I am researching ways to improve the applicability and fidelity of models that
predict the behaviour of lithium-ion batteries, this is achieved through develop-ing experimental methods for their parameterisation.
I am a first year PhD student in Prof. Abbie Mclaughlin’s group. My research focuses on investigating new materials which can be utilised for the electrolyte layer of solid oxide and proton conducting fuel cells.
I am a third year PhD student in Prof. Abbie Mclaughlin’s group. In 2018, I was awarded a PhD Scholarship from The Carnegie Trust for the Universities of Scotland to study unprecedented electronic properties in layered oxypnictide materials. This work involves the use of X-ray and neutron diffraction tech-niques as well as electrical transport measurements.
Dr Paul Sharp, University of Liverpool, UK
Dr Eve Wildman, University of Aberdeen, UK
Dr Anna Regoutz, University College London, UK
Dr Ulderico Ulissi,Nissan Motor Co., Ltd. UK
Dr Pooja Goddard, Loughborough University, UK
Dr Lucy Clark, University of Birmingham, UK
Invited Speakers
Dr Lucy Clark
School of Chemistry,University of Birmingham, UK
Exploring quantum materials and a path to a career in academia
Quantum materials research is an exciting field that brings together scien-tists from a diverse range of backgrounds, including solid-state chemistry, condensed matter physics and materials engineering. Quantum materials are those whose properties are uniquely determined by quantum mechan-ical effects that remain evident at high-temperatures and macroscopic length-scales. My research group at the University of Birmingham is ded-icated to the design and synthesis of novel quantum materials, as well as exploring the unusual functionality that emerges from them. In this talk, I will aim to give you an insight into my motivations for working in this area of solid-state chemistry, highlighting some of the recent work by the early-career researchers in my group. Along the way, I will also explore my route along the academic career path to date, sharing both successes and failures and what I have learnt from them.
Lucy was awarded her PhD in Chemistry from the University of Edinburgh in 2013, where she worked under the supervision of Prof J. Paul Attfield FRS. Her thesis de-tailed the synthesis and study of novel mixed anion materials, for which she made extensive use of powder neutron diffraction methods. Upon completion of her PhD studies, Lucy took up a post-doctoral research position in the group of Prof Bruce D. Gaulin in the Department of Physics and Astronomy at McMaster University, Canada. There, she applied inelastic neutron scattering to the study of geometrically frustrat-ed magnets. Lucy then returned to the UK to take up a post-doctoral research posi-tion in the School of Chemistry at the University of St Andrews to develop solvother-mal synthetic strategies for the discovery of new magnetic materials. Before taking up her current position of Senior Lecturer in the School of Chemistry at the Universi-ty of Birmingham in 2020, Lucy held a Materials Innovation Factory lectureship at the University of Liverpool from 2017.
Dr Eve Wildman
University of Aberdeen, [email protected]
Structure-Property Relationships Using a Combination of Diffraction and Impedance Techniques
Solid state perovskite-based oxides are an incredibly versatile chemical backdrop for many advanced materials. They are increasingly important in the development of future technologies as they have applications in electrochemical conversion devices and spintronics. My work at the UoA focuses typically on the development of new materials with superior elec-tro-physical properties, which are inherently tied to the crystal structure of the unit cell adopted. I will talk about how Ac impedance spectroscopy can be utilised in collaboration with diffraction techniques such as x-ray and high-resolution neutron diffraction, at facilities like as ISIS Neutron and Muon Source (UK) and the ILL facility (France). Together these tech-niques can be used to characterise important materials; from solid state lithium ion electrolytes to fast oxide ion conductors.
Eve completed her PhD under the supervision of Professor Jan Skakle at the Univer-sity of Aberdeen (UoA) in 2013. Her thesis was on the structure-property relations of hexagonal perovskite derivatives. She also carried out work on the exotic magnetic properties of manganese pnictides during this time, which led to a subsequent EPSRC funded post-doctoral position under the supervision of Professor Abbie McLaughlin. After a short post-doctoral stint in collaboration with St Andrews on the structure and synthesis of niobium molybdate proton conductors, Wildman joined the faculty of the UoA in 2019. After getting over the shock of lecturing for the first time and all of the dreaded administration duties that come with a lectureship, Eve was recently awarded a Carnegie Research Incentive Grant in order to advance her research into the local structure of novel ionic conductors. A circular economy approach to lithium battery recycling has become increasingly important, and Eve has received funding from the Scottish Funding Council to explore the efficiency of locally produced bio-waste in the recycling process.
Dr Paul Sharp
Department of Chemistry,University of Liverpool, UK
[email protected]: @DrPaulSharp
Paul Sharp was awarded a PhD in Physics from the University of York in 2016. His PhD research concerned the development of the metric space approach to quantum mechanics, and the application of this approach to Density Functional Theory. Fol-lowing this, he worked in a joint theory-experimental group in the Department of Chemistry at the University of Liverpool where his research focussed on developing computational methods for materials discovery. He is the author of the crystal struc-ture prediction code ChemDASH, which implements these new approaches. He has just started a new position as a computational physicist based in Daresbury Labo-ratory working with the STFC Scientific Computing Department and the SuperSTEM electron microscopy facility.
Chemically directed structure evolution for crystal structure prediction
Discovering new materials is essential to fuel the technological advances required to tackle major scientific challenges such as developing sustain-able energy technologies and tackling climate change. The starting point for finding new materials is determining the crystal structure for the composition of interest, which is the task of crystal structure prediction. There are a range of crystal structure prediction methods, many of which are implemented in high profile software packages. These methods often involve evolving an initial structure, or set of structures. My research has involved developing a new method of evolving structures for crystal struc-ture prediction, known as chemically directed swapping, which uses chem-ical models to ensure we swap atoms in the least favourable chemical en-vironments. In this talk, I will introduce the ideas behind crystal structure prediction, and detail the chemically directed swapping method, its imple-mentation in the ChemDASH code, and how this has led to the discovery of new materials.
Dr Anna Regoutz
Department of Chemistry,University College London, UK
Twitter: @bluebananna
Dr Anna Regoutz is a Lecturer in Materials Chemistry in the Department of Chem-istry at University College London. She is a CAMS-UK Fellow and holds a Visiting Sci-entist position at Diamond Light Source. Her research focus lies on bulk, thin film, and nano materials for application in devices, including power electronics, memory, and biosensors. A big focus of her work is the development and application of X-ray spectroscopy methods to bulk materials and surfaces/interfaces in electronic devices. Anna is an IUPAC Periodic Table of Chemists awardee and the recipient of the 2020 Royal Society of Chemistry’s Joseph Black Award.
A Whistle-Stop Tour through X-ray Photoelectron Spectroscopy
X-ray photoelectron spectroscopy (XPS) is based on the photoelectric ef-fect and has its beginnings in the ground breaking work of Kai Siegbahn, who received the Nobel Prize in Physics in 1981 for the development of the technique. XPS can non-destructively probe the chemical composition, local chemical environments, and electronic structure of matter, and since its invention has been applied to a vast range of materials, including sol-ids, liquids, and gases. The most common variety of XPS uses soft X-ray sources, e.g. Al K at 1.5 keV, giving extremely surface sensitive results prob-ing only the first few nanometres of a sample’s surface making it ideally placed to explore a wide range of technologically relevant materials.
This talk will give a very short introduction to the general principles and capabilities of the technique as well as provide an overview of facilities available in the UK and further afield. It will cover recent developments and emerging techniques and explore selected application areas in solid state chemistry.
Dr Ulderico Ulissi
Battery Research EngineerResearch and Advanced Engineering
Nissan Motor Co., Ltd. UKTwitter: @UldericoUlissi
Ulderico joined Nissan Motor in July 2019 as Battery Research Engineer. He is the technical coordinator for research projects on next-generation electrochemical ener-gy storage technologies at the Nissan Technical Centre Europe. In his free time, he is also editing a book for Elsevier on the application of nanomaterials for electrochemi-cal energy storage.Previously, he worked at OXIS Energy Ltd as Senior Scientist and Technical Leader for H2020 projects. He has published 16 peer-reviewed papers and filed four patents, in collaboration with several industrial partners such as BMW AG, Samsung R&D Japan, EVONIK Ind. AG, OXIS Energy Ltd. His main areas of expertise are solid-state and high energy lithium-ion batteries, with a particular focus on negative electrode materials and novel electrolyte formulations. He was awarded his doctorate (chemistry) in 2017 from the Karlsruhe Institute of Technology (Germany). Ulderico received his BSc and MSc degrees in Industrial Chemistry from the University of Rome “La Sapienza” (Ita-ly).
Bridging the gap between industry and academia
During his talk, he will focus on how to effectively approach and communi-cate with industry from a scientific point of view. He will be touching on top-ics such as scientific integrity, and the downsides of the “publish-or-perish” approach. Finally, he will give a personal perspective on how important it is to work in teams with good coaching, mentorship, and open collaborations/discussions to foster more accessible, open and inclusive scientific research efforts.
Dr Pooja Goddard
Loughborough University, UKTwitter: @GoddardPooja
I am a Senior Lecturer in Chemistry within the School of Science, Loughborough Uni-versity. My research focuses on computational studies of fundamental processes in complex materials at the atomic/quantum scale. This requires a good understanding of the structural, electronic, magnetic and transport properties which are crucial in identifying novel functional materials for sustainable energy and or catalytic appli-cations.
I am an avid baker and love to cook, especially for my friends, colleagues and loved ones. I love being outdoors, usually hiking, cycling or gardening. Other than that, I en-joy playing as well as watching various sports such as Badminton with the staff club at Loughborough. I also love to read historical fiction and try to paint with watercol-ours or acrylics to relax and switch off from work.
My journey and beyond
Whilst many young people don’t know what they want to do in life, I was very clear from the age of five that I wanted to be a “doctor for children”, yes that’s right a paediatrician.
I am clearly not a medic – so what happened?
In this talk I hope to share my journey to becoming a Senior Lecturer at Loughborough University.
The compromises, the sacrifices but also the joys and opportunities. A journey of research and teaching with the things I love most about my job and the regrets.
There will be a combination of research stories with personal endeavours in the hope that this will inspire each of you to pursue your own journeys and have some fun along the way.
Acquire scholarship and share knowledge and most importantly be the best you can!
Joining Instructions
A joining link will be sent by the 21st September 2020, once registration closes on the 18th September.
Please do not share this link with others. Our license has a limited capacity and we don’t want those who have registered formally to miss out on the meeting.
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Twitter Poster Competition
The competition will be taking place:
9:00 - 18:00 (BST) on
Tuesday 22nd September 2020.
Please make sure your poster is live by these times and use the #2020ECRsscg hashtag and tag the RSC Solid State Chem group account @SscgR.
Organisers will be in touch after registration closes to obtain your Twitter handle and poster
#2020ECRsscg
Oral Abstracts
Day 1
Tuesday 22nd September 2020
10:00 - 17:00 (BST)
Social 17:00 - 18:00
Session 110:15 - 11:45
Session 1: 10:45 - 11:00
Non-magnetic cations can drive magnetic interactions in double perovskites
Otto Mustonen,1 Charlotte Pughe,1 Helen Walker,2 Heather Mutch,1 Gavin Stenning,2 Fiona Coomer3 and Edmund Cussen.1
1 University of Sheffield, 2 ISIS Neutron and Muon Source,
3 Johnson Matthey Battery Materials.
B-site ordered double perovskites A2B’B’’O6 have a number of applications as magnetic materials.1 The main magnetic interactions in oxides such as perovskites are superexchange interactions mediated by oxygen anions. Recently, it has been shown that diamagnetic d10 or d0 cations can have a significant effect on these superexchange interactions due to orbital hybridization.2 However, this d10/d0 effect has not been studied in detail in a system without other competing effects such as structural differences, antisite disorder or spin-orbit coupling.
Here we present a comparison of 3d5 Mn2+ compounds Ba2MnTeO6 and Ba2MnWO6 with d10 Te6+ or d0 W6+ diamagnetic cations on the B’’ site, respectively.3,4 This is the simplest possible system for investigating the d10/d0 effect, as both compounds are cubic with nearly identical bond lengths and angles (<0.5% difference). Neutron diffraction experiments revealed that the compounds have different magnetic structures: Ba2MnTeO6 is a Type I antiferromagnet while Ba2MnWO6 is a Type II antiferromagnet. This is explained by the d10/d0 effect. The 4d10 Te orbitals do not hybridize with O 2p, which results in a strong J1 interaction and Type I structure. The d0 W orbitals strongly hybridize with O 2p, which suppresses J1 and enhances the J2 interaction leading to a Type II structure.3,4
This d10/d0 effect is observed in a large number of 3d transition metal double perovskites: d10 cations promote J1 interactions while d0 cations promote J2 interactions. This effect can be used as a design principle for new magnetic materials. Moreover, it can be used to tune magnetic interactions. We have previously demonstrated this in the Cu2+ double perovskite series Sr2CuTe1-xWxO6, where the magnetic ground state can be tuned from Néel order to a spin-liquid-like state to Type II order.5
Figure 1. The double perovskite structure of Ba2MnTeO6 and Ba2MnWO6. d10 cations on the B’’ site lead to Type I order and d0 cations to Type II order.
References 1 S. Vasala and M. Karppinen, Progress in Solid State Chemistry, 2015, 43, 1. 2 M. Zhu et al., Physical Review Letters, 2014, 113, 076406. 3 O. Mustonen et al., Chemistry of Materials, 2020, 32, 7070. 4 H. Mutch et al., Physical Review Materials, 2020, 4, 014408. 1 O. Mustonen et al., Nature Communications, 2018, 9, 1085.
A Nuclear and Magnetic Structure Study of the Oxypnictide Sr2Mn2.23Cr0.77As2O
Gaynor Lawrence,1,2 Clemens Ritter2 and Abbie Mclaughlin.1 1 Department of Chemistry, University of Aberdeen, Aberdeen, UK
2 Institut Laue-Langevin, Grenoble, France.
Figure 1: The crystal and magnetic structures of Sr2Mn2CrAs2O2 below 135 K (left) and above 167 K (right)..
Layered oxypnictides have been investigated in order to discover their magnetic and electrical behaviour. Sr2Mn3As2O2has two different manganese positions1 the first (M) found to have square planar MnO2 arrangement and the second position (M’) forming Mn2As2 tetrahedral layers. Magnetically this material has a G-type antiferromagnetic (AFM) ground state in the Mn2As2 layers with a Néel temperature of 340 K. A related material, Sr2Cr3As2O2, shows a different AFM structure. The Cr2As2 layers order into a C-type antiferromagnetic arrangement along c at 590 K. The spins flip into the ab plane below 291 K. At the same time antiferromagnetic order is established in the CrO2 layer2.
In order to further investigate magnetic interactions in layered oxypnictides, Sr2Mn2.23Cr0.77As2O2 has been synthesised3. The nuclear and magnetic structures have been determined from neutron and x-ray synchrotron diffraction measurements. Cation order is present between Mn and Cr, with Cr predominantly occupying the square planar MO2
2- site. Below 410 K the magnetic moments of the M2+ ions in the arsenide layers exhibit G-type antiferromagnetic order. The Mn/Cr moments within the MO2
2- layer order below 167 K with a K2NiF4-type- antiferromagnetic structure which induces a spin-flip of the M’2+ magnetic moments from a G- to C-type antiferromagnetic arrangement. The results demonstrate that the superexchange interactions are finely balanced in this sample.
References 1 S. L. Brock, N. P. Raju, J. E. Greedan, S. M. Kauzlarich, Journal of Alloys and Compounds, 1996, 237, 9-19. 2 J. Liu, J. Wang, J. Sheng, F. Ye, K. M. Taddei, J. A. Fernandez-Baca, W. Luo, G. Sun, Z. Wang, H. Jiang, G. Cao, W. Bao, Physical Review B. 2018, 98, 134416. 3 G. B. Lawrence, E. J. Wildman, G. B. G. Stenning, C. Ritter, F. Fauth, A. C. Mclaughlin, Inorganic Chemistry, 2020, 58, 7553-7560.
Session 1: 11:00 - 11:15
Structural and magnetic properties of hexagonal Ba3Tb(BO3)3
Nicola D. Kelly, Cheng Liu and Siân E. Dutton
Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
Borates with the general formula Ba3Ln(BO3)3 are of interest for optical applications.1 Structural studies in the 1990s found that the compounds with larger lanthanides, Ln = Pr–Tb, crystallise in a trigonal unit cell with the Ln3+ ions arranged in closely spaced chains, while smaller ions (Y, Dy–Lu) favour a hexagonal cell with a quasi-2D triangular lattice of Ln3+ ions (Fig. 1).2 The heavier borates were investigated by Gao et al., whose magnetic susceptibility data showed antiferromagnetic interactions with no magnetic ordering above 2 K, suggesting that the compounds are magnetically frustrated.3
Fig. 1: Comparison of Ln3+ ion arrangement in polymorphs of Ba3Ln(BO3)3: (a) Heavier lanthanides in triangular layers, P63cm; (b) Lighter lanthanides in closely spaced chains, R-3.
We have synthesised a new hexagonal, low-temperature phase of Ba3Tb(BO3)3 using solid-state methods and characterised it using powder X-ray diffraction and bulk magnetic measurements. The new phase displays magnetic behaviour similar to that of the isostructural Dy and Ho analogues. Magnetic susceptibility χ(T) shows antiferromagnetic interactions (θCW = –7.15 K) and no sharp ordering transition at T ≥ 2 K, but analysis of χ ’(T), isothermal magnetisation and heat capacity suggests the possibility of short-range ordering at T ≈ 10 K. The material exhibits an unusual inverse magnetocaloric effect at T < 4 K.4
References 1 D.-Y. Wang, T.-M. Chen and B.-M. Cheng, Inorg. Chem., 2012, 51, 2961. 2 T. N. Khamaganova, N. M. Kuperman and Zh. G. Bazarova, J. Solid State Chem., 1999, 145, 33. 3 Y. Gao, L. Xu, Z. Tian and S. Yuan, J. Alloys and Compounds, 2018, 745, 396. 4 N. D. Kelly, C. Liu and S. E. Dutton, J. Solid State Chem., accepted. arxiv:2007.15453
Session 1: 11:15 - 11:30
Chemically Tailorable Frustrated Systems: Structural Parity and Disparity in Related AM(C2O4)0.5F2 (AM = NH4+ Co2+, Cs+ Mn2+)
Alasdair J. Bradford1,2, Teng Li1, Ron Smith3, Stephen L. Lee2 and Philip Lightfoot1. 1 School of Chemistry, University of St Andrews, St Andrews, Fife, Scotland, UK,
2 School of Physics and Astronomy, University of St Andrews, St Andrews, Fife, Scotland, UK, 3 ISIS Crystallography Group, ISIS Neutron and Muon Source, STFC RAL, Didcot, UK.
In pursuit of new materials in the topical area of low dimensional and frustrated magnetic systems we are investigating a family of materials which use the oxalate ligand as a backbone from which multiple structures can be derived through combination with magnetic spin sources and additional ligand groups. We currently focus primarily on compounds which have first row transition metals as sources of magnetic spin,1,2 which can then be coupled in two-dimensional (2d) layered lattices.
Figure 1. NH4Co(C2O4)0.5F2 and CsMn(C2O4)0.5F2 along ac plane, highlighting the buckled ladder structure (Co-F-Co = 4.075Å and Mn-F-Mn = 4.030Å) {parent space group Cmmm}
Two such examples we have synthesised are the isostructural compounds AMII(C2O4)0.5F2 (AM = (NH4)Co or CsMn), shown in Fig. 1. These compounds comprise of a semi-2d layered structure where magnetic exchange coupling is split between F- coupled sheets in the ac plane and oxalate coupling (C2O4
-2) between these sheets along the b axis. The strong in-plane rectangular coupling means this system in principle maps very nicely onto a 2d Heisenberg (3d) J1/J1’ type of model, which should be completely free of any diagonal (J2) exchange coupling that might geometrically frustrate the system. Additional coupling within or between the layers may also lead to frustrated ground states, and there have been several theoretical and numerical studies of these kinds of idealised systems.3
From elastic neutron powder diffraction data, the two materials have a near identical nuclear structure at high temperature, but between 173-150 K the cobalt compound undergoes a structural transition from parent Cmmm to Cmcm while the manganese compound stays in the parent group. This symmetry breaking due to tiling of the cobalt octahedra has little effect on the magnetic superstructures both materials form at low temperatures which are highly equivalent.
References 1 W. Yao et al., Chem. Mater., 2017, 29, 6616. 2 K. Tustain et al., Inorg. Chem., 2019, 58, 11971. 3 A. Orendacova et al, Crystals, 2019, 9, 6
Session 1: 11:30 - 11:45
Session 212:00 - 13:15
Spin crossover in the Prussian blue analogue FePt(CN)6 induced by pressure or X-ray irradiation
H. L. B. Boström,1 A. B. Cairns,2 L. Liu,3 P. Lazor,3 and I. E. Collings.4 1 Department of Chemistry, Uppsala Universitet, Uppsala, Sweden,
2 Department of Materials, Imperial College London, London, UK, 3 Department of Earth Sciences, Uppsala Universitet, Uppsala, Sweden,
4 Centre of X-ray analytics, EMPA, Dübendorf, Switzerland.
Material bistability is exploited in a range of applications, since it gives access to two distinct physical property states that can be reversibly switched by external stimuli, e.g. temperature, pressure, or irradiation. Spin crossover (SCO) materials are of particular interest as their transitions between high-spin and low-spin states are coupled with changes in functionality.1 Abrupt transitions are often desirable, which requires strong interactions between the SCO centres (i.e. high cooperativity). This may be achieved by incorporating the SCO-active metal—typically FeII—into a coordination polymer.
A family of coordination polymers known for their switchable behaviour are the Prussian blue analogues with formula AxM[M’(CN)6]y (A = alkali metal, M,M’ = transition metals).2 Here, we explore the SCO transition in FePt(CN)6, which may be triggered by compression to ~0.9 GPa, but not by cooling.3 This contrasts with the related CsFeCr(CN)6, where the spin crossover occurs under near-ambient conditions.4,5 Interestingly, the spin transition of FePt(CN)6 can also be induced at lower pressures by increased X-ray radiation. The non-innocent role of X-rays will be discussed in the context of other radiation-induced structural and electronic changes in metal hexacyanoplatinates.6
Fig. 1. The pressure-induced volume change of FePt(CN)6 resulting from the spin crossover transition. The X-ray-induced spin transition at lower pressure is also indicated.
References 1 P. Gütlich, Y. Garcia and H. A. Goodwin, Chem. Soc. Rev. 2000, 29, 419-427. 2 D. Aguilà, Y. Prado, E. S. Koumousi, C. Mathonière and R. Clérac, Chem. Soc. Rev., 2016, 45, 203–224. 3 H. L. B. Boström, A. B. Cairns, L. Liu, P. Lazor and I. E. Collings, Dalton Trans., 2020, DOI: 10.1039/D0DT02036B. 4 W. Kosaka, K. Nomura, K. Hashimoto and S. I. Ohkoshi, J. Am. Chem. Soc., 2005, 127, 8590–8591. 5 D. Papanikolaou, W. Kosaka, S. Margadonna, H. Kagi, S.-I. Ohkoshi and K. Prassides, J. Phys. Chem. C, 2007, 111, 8086–8091.
6. H. L. B. Boström, I. E. Collings, A. B. Cairns, C. P. Romao and A. L. Goodwin, Dalton Trans., 2019, 48, 1647–1655.
Session 2: 12:30 - 12:45
Controlling the Growth of Metallic and Semiconducting 2D-Chalcogenide by Chemical Vapour Deposition
James P. Fraser,1 Liudvika Masaitytė,1 Juan Carlos Moreno-López,2 Stacey Laing,3 Duncan Graham,3 Thomas Pichler,2 David A. J. Moran,4 and Alexey Y. Ganin1.
1 WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK 2 University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
3WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1RD, UK.
4 School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
Molybdenum ditelluride (MoTe2) has received increasing amounts of attention over the last five years, mainly due to the interesting layer-dependent properties of its two polymorphs. In bulk form hexagonal 2H-MoTe2 is an indirect gap semiconductor but when it is thinned down to few- and monolayer samples, a direct gap of ~1.1 eV emerges. This bandgap switching is accompanied with a strong photoluminescence signal in the near IR region, making few-layer 2H-MoTe2 a potential candidate for optoelectronic devices.1 Whereas, the monoclinic 1T’-MoTe2 is a Weyl semi-metal in bulk form and has been investigated for potential applications in fields as varied as energy conversion and surface enhanced Raman spectroscopy (SERS).2,3 The polymorphism of MoTe2 provides an opportunity to exploit the influence of crystal structure on the electronic properties without the need for compositional change. The most exciting examples of this include the fabrication of 2H-MoTe2 based field effect transistors that are contacted with the 1T’ phase which show improved device performance compared to 2H devices contacted with other metals.4 However, most methods of forming 1T’-2H homojunctions rely on post-growth modification using techniques such as laser irradiation.5 In this work we show that the nature of seeding layer determines whether the atomically-thin MoTe2 film grown by chemical vapour deposition (CVD) is 1T’-MoTe2 or 2H-MoTe2. When Mo metal is used phase-pure semiconducting 2H-MoTe2 is formed as the sole product. However, using MoO3 results in the formation of phase-pure semi-metallic 1T’-MoTe2. This control over the phase growth allows for the simultaneous growth of both 2H-MoTe2 and 1T’-MoTe2 on a single substrate during one CVD reaction and without the need for any post growth modification (Figure 1).
Figure 1: Illustration of the conversion process that allows for the simultaneous growth of both 2H- and 1T’-MoTe2 on a single substrate.
Furthermore, the layer dependent properties of 1T’-MoTe2 were explored by using few-layer and bulk films as SERS substrates. When adsorbed onto few layer films rhodamine 6g dye could be detected at concentrations as low as 5 nM, remarkably the bulk films exhibited no appreciable SERS activity.
References 1 Reeves, L.; Wang, Y.; Krauss, T. F., Adv. Opt. Mater. 2018, 6, 1800272. 2 McGlynn, J. C.; Dankwort, T. ; Kienle, L. et al. Nat. Commun. 2019, 10, 4916. 3 Tao, L.; Chen, K.; Chen, Z. et al. J. Am. Chem. Soc. 2018, 140, 8696–8704. 4 Ma, R.; Zhang, H.; Yoo, Y. et al. ACS Nano. 2019, 13, 8035–8046. 5 Cho, S.; Kim, S.; Kim, J. H. et al. Science. 2015, 349, 625–628.
Session 2: 12:45 - 13:00
Reactive spark plasma sintering of BiCuSeO oxyselenides: challenges, phase formation mechanism and related thermoelectric properties
Andrei Novitskii,1 Takao Mori2,3 and Vladimir Khovaylo.1,4 1 National University of Science and Technology MISIS, Russia,
2 National Institute for Materials Science (NIMS), International Center for Materials Nanoarchitectonics (WPI-MANA), Japan,
3 University of Tsukuba, Graduate School of Pure and Applied Sciences, Japan, 4 National Research South Ural State University, Russia.
Thermoelectric materials, capable of directly converting heat energy to electrical energy based on the Seebeck effect. Performance of the thermoelectric materials can be characterised by the dimensionless figure of merit zT = α2 σ T κ−1, where α is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the total thermal conductivity. Recently, as an emerging layered oxygen-containing thermoelectric material, BiCuSeO was found to exhibit high performance in the wide temperature range with maximum zT ~1.5 at 873 K for Pb and Ca dually doped BiCuSeO.1
However, from an industrial point of view, a large zT value observed at a given temperature is not the only important parameter. The development of a straightforward scalable synthesis route appropriate for industrial mass production becomes a critical issue for thermoelectric device fabrication. Typically, synthesising polycrystalline BiCuSeO samples is a two-step solid-state reaction route (SSR) involving preparation of feedstock (typically it is already BiCuSeO single-phase) in the form of powder followed by consolidation into a dense sample suitable for transport measurements. SSR technique is cumbersome, time-consuming and energy-intensive.
In this work, we demonstrate that BiCuSeO compound can be formed in bulk directly from the raw materials through reactive spark plasma sintering (RSPS). It is shown that the density of the resultant bulks strongly depends on the chosen precursors (Bi2O3 + Bi + Se + Cu or CuO + Se +Bi), while it is independent from sintering parameters. Compared to BiCuSeO samples obtained by a conventional SSR, the electrical transport properties of the RSPS bulk were moderately affected by the sintering technique, while the lattice thermal conductivity was almost unaffected, and the figure of merit zT attained values comparable to state-of-the-art BiCuSeO. The results indicate a new scalable method for the preparation of oxyselenides.
References 1 Y. Liu, L. D. Zhao, Y. Zhu, Y. Liu, F. Li, M. Yu, D. B. Liu, W. Xu, Y. H. Lin and C. W. Nan, Adv.
Energy Mater., 2016, 6, 1–9.
Session 2: 13:00 - 13:15
Session 313:45 - 15:15
Understanding the Surface Chemistry in Tin Dioxide Gas Senors
Luisa Herring Rodriguez,1 Daniel W. Davies1, Chris Blackman1 and David O. Scanlon1-3
1 Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom,
2 Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, United Kingdom,
3 Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
Tin dioxide (SnO2) is one of the most studied and used metal oxide semiconductors and is often used in gas sensors. Despite the extensive research into SnO2 and its wide range of uses, its surface chemistry is still not fully understood. A detailed literature search of previously proposed surface structures and gas adsorption mechanisms for SnO2 reveals many conflicting models with zero consensus. This disparity between different mechanistic theories demonstrates the need for a more thorough investigation if we are to design new gas sensing materials in a methodical way in the future.
In this work, we use levels of accuracy within a Density Functional Theory (DFT) framework which have hitherto been inaccessible due to their computational expense. We initially calculate the optoelectronic properties of bulk SnO2 and systematically investigate the effect of slab and vacuum thickness on surface model validity. We go on to calculate the energetics for a range of proposed surface defects, as well as for various proposed gas adsorption sites. All of this work is done with hybrid DFT functionals that can accurately describe the localised charge density in defect and adsorption simulations.
Our initial results show that larger slab models than those previously used are required to accurately represent the SnO2 crystal structure. Our surface formation energies show the accuracy of our calculations as they fall withing the literature value range of 1.0 and 1.5 Jm-2. Overall, this work highlights how modern first-principles methods can elucidate surface phenomena in well-studied materials, and paves the way for the rational design of new inorganic compounds for gas sensing applications.
Session 3: 14:15 - 14:30
Computational investigation on the effect of hydrogenation treatment on Na2Ti3O7 anode for enhanced Na-ion storage
Yong-Seok Choi,1,2,4 Sara I. R. Costa,2,3 Nuria Tapia-Ruiz2,3 and David O. Scanlon1,2,4,5 1 Department of Chemistry, University College London, 20 Gordon street, London WC1H 0AJ, UK, 2 The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA,
UK, 3 Department of Chemistry, Lancaster University, Lancaster LA1 4YB, UK
4 Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, UK 5 Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot
OX11 0DE, UK.
Owing to its low-cost advantage, Na-ion batteries (NIBs) have been widely studied as a promising candidate competitive with conventional Li-ion batteries (LIBs) for large-scale applications. Nevertheless, the current energy-normalized cost of NIBs (0.14$/Wh−1) is more expensive than that of LIBs (0.11$/Wh−1)1 and the development of low-cost and high-capacity electrodes for NIBs are essential. Among various electrodes discovered to date, sodium titanates-based anodes arise as one of the most promising candidates due to its large abundance, nontoxicity.2 Of this family of compounds, Na2Ti3O7 and Na2Ti6O13 have attracted much attention for different reasons; Na2Ti3O7 exhibits high specific capacity (177 mAhg-1) but lacks electric/ionic conductivity and structural stability.3 In contrast, Na2Ti6O13 has high ionic conductivity and structural stability but suffers from low Na storage capacity.4 With this in mind, proper hybridization of Na2Ti3O7 and Na2Ti6O13 could break the limitations of each structure and offer a composite electrode for high performance NIBs.
Recently, experiments revealed that introducing a reducing agent of urea (CH4N2O) can hydrogenate Na2Ti3O7 and facilitate the phase transformation from Na2Ti3O7 to Na2Ti6O13.5 This suggests the hydrogenation treatment as a facile way to fabricate Na2Ti3O7/Na2Ti6O13 composite electrode. In this context, a comprehensive understanding of the phase stability of Na2Ti3O7 during hydrogenation treatment can enable further performance enhancements of sodium titanate electrodes. In this study, using density functional theory calculations, we have analyzed the effect of hydrogenation treatment on the electrochemical performance of Na2Ti3O7 anode. Phase stability calculations showed that the thermal energy applied during hydrogenation treatment enables the decomposition of Na2Ti3O7 into Na2Ti6O13. Additional calculations on band structures and their alignment revealed that the formation of Na2Ti6O13 can reduce the band gap of initial Na2Ti3O7, enhancing electrochemical performance of the electrode. The results provided here can aid designing high performance sodium titanate electrodes for future NIBs.
References 1 J. W. Choi and D. Aurbach, Nat. Rev. Mater., 2016, 1, 1-16. 2 M. M. Doeff, J. Cabana, and S. M. Shirpour, J. Inorg. Organomet. P., 2014, 24, 5-14. 3 J. Nava-Avendaño, A. Morales-García, A. Ponrouch, G. Rousse, C. Frontera, P. Senguttuvan, J. M. Tarascon, M. E. Arroyo-de Dompablo and M. R. Palacín, J. Mater. Chem. A, 2015, 3, 22280-22286. 4 K. Cao, L. Jiao, W. K. Pang, H. Liu, T. Zhou, Z. Guo, Y. Wang and H. Yuan, Small, 2016, 12, 2991-2997. 5 S. I. R. Costa, Y. S. Choi, A. J. Fielding, A. J. Naylor, J. M. Griffin, Z. Sofer, D. O. Scanlon, N. T. Ruiz, Chem. A Eur. J., 2020, https://doi.org/10.1002/chem.202003129
Session 3: 14:30 - 14:45
Bandgap Lowering in Lead-Free Cs2Ag(SbxBi1-x)Br6 Double Perovskite Alloys Seán R. Kavanagh,1-4 Zewei Li,5 Robert G. Palgrave,1 Daniel W. Davies,1 Richard H. Friend,5
Aron Walsh2,3,6, David O. Scanlon1,3,7 and Robert L. Z. Hoye.2 1 Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
2 Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, UK
3 Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
Double perovskites have emerged as promising candidate materials for high-performance next-generation optoelectronic technologies, owing to the ability to replace the toxic Pb2+ cation with a pair of more benign cations (e.g. Ag+ and Bi3+), while preserving the perovskite crystal structure.[1] Although double perovskites are air-stable and have demonstrated long electron/hole carrier lifetimes,[2] most double perovskites, including the prototypical Cs2AgBiBr6, have prohibitively wide electronic bandgaps, limiting photoconversion and photocatalytic efficiencies.[3]
In this work, we demonstrate a novel route to lowering the bandgap of these materials through nonlinear mixing of metal-cation orbitals.[4] Via synthesis and characterisation of phase-pure Cs2Ag(SbxBi1-x)Br6 thin films, with the mixing parameter x tuneable over the entire composition range, we observe this system to disobey Vegard’s law, exhibiting significant bandgap bowing, such that the mixed alloy demonstrates a smaller electronic bandgap than either of the pure materials. We investigate the possible mechanisms for this nonlinear bandgap variation through relativistic hybrid Density Functional Theory (DFT) calculations, combined with in-depth measurements of the composition, phase and grain structure to yield detailed understanding of the underlying chemical origins.
The staggered ‘Type II’ bandgap alignment of these materials, arising from the relativistic contraction of the bismuth 6s lone-pair orbital and subsequent effects on antibonding interactions with the anion p states, is found to yield non-linear orbital mixing upon alloying, reducing the electronic bandgap.
Our work reveals a promising pathway to bandgap engineering in double perovskite alloys, such that they may be better suited to photovoltaic (indoor PV – Eg, ideal = ~2 eV or tandem top-cells - Eg, ideal = 1.7-1.9 eV) or photocatalytic applications.
References
1 C. N. Savory, A. Walsh and D. O. Scanlon, ACS Energy Lett., 2016, 1 949–55 2 A. H, Slavney, T. Hu, A. M. Lindenberg and H. I Karunadasa, J. Am. Chem. Soc., 2016, 138 2138–
41
3 Y.-T. Huang, S. R. Kavanagh, D. O. Scanlon, A. Walsh and R. L. Z. Hoye. 2020, Perovskite-Inspired Materials for Photovoltaics -- From Design to Devices, arXiv:2008.08959 [physics.app-ph]
4 Z. Li, S. R. Kavanagh, M. Napari, R. G. Palgrave, M. Abdi-Jalebi, Z. Andaji-Garmaroudi, D.W. Davies,
M. Laitinen, J. Julin, R. H. Friend, D. O. Scanlon, A. Walsh and R. L. Z. Hoye 2020 Bandgap Lowering in Mixed Alloys of Cs2Ag(SbxBi1-x)Br6 Double Perovskite Thin Films arXiv:2007.00388 [cond-mat]
Session 3: 14:45 - 15:00
Optimising Transparent Conducting Oxides for Thermoelectric Applications
Kieran B. Spooner,1,2 Alex M. Ganose1,2 and David O. Scanlon. 1,2,3 1 Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
2 Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, UK, 3 Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot,
Oxfordshire OX11 0DE, UK.
Thermoelectrics are materials which can convert heat into electricity and vice versa, which could
generate renewable energy and recycle waste heat. Currently, they have low efficiencies, measured
as dimensionless figures of merit, ZTs, and are often made from rare or toxic materials such as PbTe
and Bi2Te3. Transparent conducting oxides (TCOs), which are widely commercialised in
touchscreens and photovoltaics, could be rapidly deployed to slow global heating, if they could be
made into efficient thermoelectrics, but no systematic study has assessed their potential. Using
density functional theory (DFT), we analysed the electronic and thermal properties of the TCOs
BaSnO3, CdO, SnO2 and ZnO. We demonstrate lattice thermal conductivity (κl) is the limiting factor
of the ZTs, and that extremely long phonon mean free paths of up to 10 μm are the cause. We further
show this makes SnO2 and ZnO ideal candidates for nanostructuring to suppress thermal transport,
backed up by literature experimental results for ZnO;1 and BaSnO3 could be an excellent
thermoelectric due to its naturally short phonon mean free paths. This demonstrates a thorough ab
initio understanding of the κl of oxide thermoelectrics is necessary to fully analyse their potential, and
to provide guidelines for how to maximise performance.
References 1 M. Ohtaki, K. Araki and K. Yamamoto, J. Electron. Mater., 2009, 38, 1234. 2 K. B. Spooner, A. M. Ganose and D. O. Scanlon, J. Mater. Chem. A, 2020, 24, 11948.
Session 3: 15:00 - 15:15
Session 415:30 - 17:00
Incommensurate-commensurate transition in the geometric ferroelectric LaTaO4
1 Grant W. Howieson, 1 Shitao Wu, 2 Alexandra S. Gibbs, 1 Wuzong Zhou, 1, 3 James F. Scott and
1 Finlay D. Morrison. 1 EaStCHEM, School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, United
Kingdom 2 ISIS Facility, Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, United Kingdom
3 SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
The layered perovskite LaTaO4 has been synthesized to be stable in both (polar) orthorhombic and (non-polar) monoclinic polymorphs at ambient conditions. Although the structural transition between monoclinic and orthorhombic phases has been well established there is some controversy regarding a further, unidentified transition around 500 K. Here we identify this as an incommensurate-commensurate first order transition between incommensurate Cmc21(α00)0s0 and commensurate Cmc21 orthorhombic phases. Transmission electron microscopy indicates partially ordered stacking of different structural units in a, identifying the local cause for the modulation, whereas variable temperature powder neutron diffraction has shown the overall macroscopic modulation vector, q ≈ (0.456, 0, 0) – roughly a 2.2 expansion in a, corresponding to an approximate 11a commensurate superunit cell dimension. The modulation shows a continuous temperature dependence until transitioning to the basic (commensurate) cell at TIC-C. Doping the inter-layer La sites with smaller Nd cations stabilises the incommensuration to higher temperature, suggesting the modulation is geometrically-driven at the A-site.
Session 4: 16:00 - 16:15
Deciphering the structure of complex nanocrystalline materials from
TEM and XRPD
Magdalena O. Cichocka,1 Zhehao Huang 1 and Xiaodong Zou 1 1 Department of Materials and Environmental Chemistry, Stockholm University, Stockholm,
Sweden
Knowledge of the three-dimensional (3D) atomic structures of materials is essential to a fundamental understanding of their properties. Structure determination is the first step towards understanding their functionalities that are often hidden in the details at the nanoscale. For this reason, it is very important to choose the right strategy to bring new insights into the structure analysis of complex materials. A structural study of beam-sensitive or uniquely disordered materials can be very complicated. Although there are already existing methods such as X-ray powder diffraction (XRPD), the data may exhibit reflection overlap or other problems that make structure determination difficult. To overcome these limitations for nanocrystalline materials, complementary characterization techniques can be used.
Here, I will focus on 3D electron crystallography (single-crystal electron diffraction and high-resolution transmission electron microscopy) methods that have grown during the past years as hybrid methods for structure determination. Based on the presented materials 1, 2, I will also emphasize that any kind of challenges can be a driving force for method development.3 Finally, I will try to describe the general procedures for ab initio structure elucidation of disordered nanocrystals.
References 1 M. O. Cichocka, Y. Lorgouilloux, S. Smeets, J. Su, W. Wan, P. Caullet, N. Bats, L. B. McCusker, J.-L. Paillaud, X. Zou, Cryst. Growth Des., 2018, 18, 2441-2451. 2 M. O. Cichocka, Z. Liang, D. Feng, S. Back, S. Siahrostami, X. Wang, L. Samperisi, Y. Sun, H. Xu, N. Hedin, H. Zheng, X. Zou, H.-C. Zhou, Z. Huang, J. Appl. Chem. Sci., 2020, doi.org/10.1021/jacs.0c06329. 3 M. O. Cichocka, J. Ångström, B. Wang, X. Zou, S. Smeets, J. Appl. Cryst., 2018, 51, 1652-1661.
Session 4: 16:15 - 16:30
High-rate Lithium-ion Batteries with Complex Mixed Metal Oxide Anodes
Kent J. Griffith1,2 and Clare P. Grey2 1 Departments of Chemistry and Materials Science and Engineering, Northwestern University,
Evanston, IL 60208 USA, 2Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
Faster battery charging is desired across the gamut of portable electronics and is particularly critical to encourage widespread adoption of electric vehicles. However, there are inherent safety risks associated with charging lithium-ion batteries at high current densities. Resistive heat generation can lead to thermal runaway and dendrites can form on low voltage (vs. Li+/Li) anodes including graphite, silicon, and lithium, further increasing the proclivity for a battery fire or explosion.
Due to the safety challenges associated with fast charging, higher voltage anodes have been explored; the most established of these is the commercialized lithium titanate spinel (Li4Ti5O12), which intercalates lithium at 1.55 V vs Li+/Li. Li4Ti5O12 exhibits good rate performance and cycle life but it suffers from relatively low gravimetric and volumetric energy density as well as gassing issues. Surface electrolyte decomposition and gassing are particularly problematic with high surface area nanostructured morphologies that are designed to improve high-rate capabilities. Recently, several niobium-based oxides have been introduced that exhibit rapid Li insertion and extraction1–3 and we have shown that this performance can be extended to μm solid-state diffusion lengths in complex oxides.1,4–7 The prospect of high-rate energy storage in dense, bulk niobium-based oxides can lead to substantially larger volumetric energy densities than Li4Ti5O12, opening the possibility of new applications of fast charging.
To understand this unique rate capability, the atomic and electronic structure of homologous series of titanium niobium oxides and niobium tungsten oxides have been examined. Structure–electrochemistry relationships have been probed with tools including high-rate operando synchrotron diffraction, multinuclear and pulsed-field-gradient NMR spectroscopy, X-ray spectroscopy, neutron diffraction, magnetic susceptibility, and electronic conductivity measurements (Figure 1). The experimental evidence is correlated with ab initio studies6,8 on the role of cation disorder, diffusion pathways and activation energies, electronic structure, and atomic structure evolution.
References 1 K. J. Griffith, K. M. Wiaderek, G. Cibin, L. E. Marbella and C. P. Grey, Nature, 2018, 559, 556–563. 2 B. Guo, X. Yu, X.-G. Sun, M. Chi, Z.-A. Qiao, J. Liu, Y.-S. Hu, X.-Q. Yang, J. B. Goodenough and
S. Dai, Energy Environ Sci. 2014, 7, 2220–2226. 3 V. Augustyn, J. Come, M. A. Lowe, J. W. Kim, P.-L. Taberna, S. H. Tolbert, H. D. Abruña, P. Simon
and B. Dunn Nat. Mater. 2013, 12, 518–522. 4 K. J. Griffith, A. Senyshyn and C. P. Grey Inorg. Chem. 2017, 56, 4002–4010. 5 K. J. Griffith, A. C. Forse, J. M. Griffin and C. P. Grey J. Am. Chem. Soc. 2016, 138, 8888–8899. 6 K. J. Griffith, I. D. Seymour, M. A. Hope, M. M. Butala, L. Lamontagne, M. B. Preefer, C. P. Koçer,
A. J. Morris, M. J. Cliffe, S. E. Dutton and C. P. Grey J. Am. Chem. Soc. 2019, 141, 15121–15134 7 K. J. Griffith and C. P. Grey Chem. Mater. 2020, 32, 3860–3868. 8 C. P. Koçer, K. Griffith, C. P. Grey and A. J. Morris J. Am. Chem. Soc. 2019, 141, 15121–15134.
Figure 1 – (left) Diffusion pathways, (middle) 6Li solid-state NMR spectra, and (right) electronic property evolution of TiNb2O7 as a function of Li.
Session 4: 16:30 - 16:45
Elucidating Nanoscale Structure of Spinel Iron Oxide Nanocrystals Using Pair Distribution Function Analysis of Total X-ray Scattering Data: Influence of Nanocrystal Structure on
Growth
Susan R. Cooper,1 Kenyon L. Plummer,2 Samantha L. Young 2 Meredith C. Sharps,2 Alexia G. Cosby,2 Randall O. Candler,2 Darren W. Johnson,2 Kirsten M. Ø. Jensen1 and James E. Hutchison2
1 University of Copenhagen,
2 University of Oregon
Spinel iron oxide nanoparticles below 10 nm in diameter have been reported to have more tetrahedrally coordinated cation vacancies, which is hypothesized to be due to either size-dependent nanoscale structure or the mechanism of formation.1,2 Here we use a synthetic technique that uses catalytic esterification to form nanocrystals which allows for layer by layer growth of nanoparticles enabling us to monitor changes in structure with size.3 In addition, we employ pair distribution function analysis of total X-ray scattering data to determine nanoscale structure of nanocrystals from 3-10 nanometres and to monitor the reaction in situ. We verify that there are more tetrahedrally coordinated cation vacancies for smaller nanocrystal diameters and correlate this nanoscale structure to the growth behaviour of the nanocrystals.4 The tetrahedrally coordinated cation sites are expected to be especially reactive2 and we observe a slower growth rate once tetrahedrally coordinated cation sites are fully occupied. In addition, we determine how tetrahedrally coordinated cation sites evolve during the reaction by analysing in situ total X-ray scattering data. From this study, we gain insight into how evolving nanoscale structure impacts nanoparticle formation. This is also an example of how pair distribution function analysis of total X-ray scattering data can be used to gain mechanistic information about nanomaterials enabling rational design of nanoparticles.
References
(1) Jensen, K.; Andersen, H. L.; Tyrsted, C.; Bøjesen, E. D.; Dippel, A.-C.; Lock, N.; Billinge, S. J. L.; Iversen, B. B.; Christensen, M. ACS Nano 2014, 8, 10704–10714.
(2) Auffan, M.; Rose, J.; Proux, O.; Borschneck, D.; Masion, A.; Chaurand, P.; Hazemann, J.-L.; Chaneac, C.; Jolivet, J.-P.; Wiesner, M. R.; et al. Langmuir 2008, 24, 3215–3222.
(3) Cooper, S. R.; Plummer, L. K.; Cosby, A. G.; Lenox, P.; Jander, A.; Dhagat, P.; Hutchison, J. E. Chem. Mater. 2018, 30, 6053–6062.
(4) Cooper, S. R.; Candler, R. O.; Cosby, A. G.; Johnson, D. W.; Jensen, K. M. Ø.; Hutchison, J. E. ACS Nano 2020
Session 4: 16:45 - 17:00
Cheese & Wine Social
17:00 - 18:00
The organisers will set up breakout rooms if you wish to socialise.
Have some snacks and a drink ready (doesn’t have to be alcoholic, we highly
rate tea!).
Day 2
Wednesday 23rd September 202010:00 - 14:30 (BST)
Session 510:15 - 11:30
Computational investigation of earth abundant electrolytes of the M3AlP2 (M = Li, Na) system
Arthur B. Youd1,2, D. W. Davies1,2 Christopher N. Savory1,2,3 and David O. Scanlon1,2,3,4,*
1Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom;
2Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, United Kingdom;
3The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom;
4Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
* [email protected] Earth abundant solid state electrolytes are a vital paradigm in the realisation of truly sustainable solid-state rechargeable batteries. These materials must maintain a tight balancing act between chemical stability, ion mobility and earth abundance. Recent work has shown promising Li ion mobility in phosphidoaluminates owing to the favourable alignment of AlP4 tetrahedra.
1 The final characterisation of this as well as the exact Li migration mechanism is not fully understood. The sodium analogue (Na3AlP2) shares significant structural features which may make it a possible candidate for sodium ion electrolytes.2 In this study, we have performed ab initio Density Functional Theory calculations on M3AlP2 (M = Li, Na) to predict and critically assess their ion transport properties. The methodology makes use of an array of python-based tools to generate structures (pymatgen)3, defective supercells (bsym)4 and create workflows (atomate)5 to perform high throughput calculations. Ab initio molecular dynamics (AIMD) and nudged elastic band (NEB) approaches are employed to examine the ion mobility and diffusion coefficients of M3AlP2 with a view to assessing its suitability as an electrolyte. The thermodynamic stability is window is calculated with electronic alignment relative to cathodes. Dynamic stability of these electrolytes is investigated with phonon analysis within the harmonic approximation. While quantitative analysis of AIMD informs the extent of diffusion, qualitative directional analysis gives insights into the preferred route of diffusion as well as help propose specific mechanisms for ion diffusion. Through multiple AIMD runs we can extract temperature dependent behaviour and compare with microscopic activation barriers from NEB. These results allow us to elucidate the favourable mechanism in the phosphidoaluminates and thus draw conclusions on promising future developments for solid state electrolytes in both Li-ion and Na-ion batteries.
1. T. M. F. Restle, C. Sedlmeier, H. Kirchhain, W. Klein, G. Raudaschl-Sieber, V. L. Deringer, L. van Wüllen, H. A. Gasteiger, T. F. Fässler, Angew. Chem. Int. Ed. 2020 , 59 , 5665.
2. Somer, M., Carrillo-Cabrera, W., Peters, E.-M., Peters, K., & von Schnering, H. G. (1995). Crystal structure of trisodium catena-di-μ-phosphidoaluminate, Na3AlP2, Zeitschrift für Kristallographie - Crystalline Materials, 210(10), 777-777.
3. Shyue Ping Ong, William Davidson Richards, Anubhav Jain, Geoffroy Hautier, Michael Kocher, Shreyas Cholia, Dan Gunter, Vincent L. Chevrier, Kristin A. Persson, Gerbrand Ceder, Python Materials Genomics (pymatgen): A robust, open-source python library for materials analysis, Computational Materials Science, Volume 68, 2013, Pages 314-319
4. Bsym: Morgan, (2017), bsym: A basic symmetry module, Journal of Open Source Software, 2(16), 370,
5. Mathew, K., Montoya, J. H., Faghaninia, A., Dwarakanath, S., Aykol, M.,Tang, H., Chu, I., Smidt, T., Bocklund, B., Horton, M., Dagdelen, J., Wood, B., Liu, Z.-K., Neaton, J., Ong, S. P., Persson, K., Jain, A., Atomate: A high-level interface to generate, execute, and analyse computational materials science workflows. Comput. Mater. Sci. 139, 140–152 (2017).
Session 5: 10:45 - 11:00
Synthetic Pathway Determines the Non-equilibrium Crystallography of Li- and Mn-rich Layered Oxides
Ashok S. Menon1, Seda Ulusoy2, Dickson O. Ojwang1, Lars Riekehr§, Christophe Didier3,4, Vanessa K. Peterson3,4, Germán Salazar-Alvarez2, Peter Svedlindh2, Kristina Edström1, Cesar Pay Gomez1 and William
R. Brant1 1 Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-75121 Uppsala, Sweden 2 Department of Materials Science and Engineering, Uppsala University, Box 35, SE-75103, Uppsala, Sweden 3 Institute for Superconducting & Electronic Materials, Faculty of Engineering, University of Wollongong, Wollongong 2522, Australia 4 Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
Li- and Mn-rich layered oxides show significant promise as electrode materials for future Li-ion batteries.1 However, accurate descriptions of its crystallography remain elusive, with both single-phase solid solution2 and multi-phase structures3 being proposed for high performing materials such as Li1.2Mn0.54Ni0.13Co0.13O2 (LMNCO). Herein, we report the synthesis of single- and multi-phase variants of this material through sol-gel and solid-state methods, respectively, and conclusively demonstrate that its crystallography is a direct consequence of the synthetic route and not an inherent property of the composition, as previously thought. This was accomplished through an array of techniques including X-ray and neutron powder diffraction, Raman spectroscopy, magnetic measurements and electron microscopy that probe the bulk and local structure, followed by in situ methods to map the synthetic progression. Considering that its anionic redox and electrochemical behaviour are explained based on the crystallography, clarifying the structural ambiguities plaguing this material is an important step towards harnessing its potential as an electrode material.
Figure 1: (Left) Single- and multi-phase LMNCO models along with the corresponding cation ordering.
(Right) Structural refinement of sol-gel (red) and solid-state (black) LMNCO structures against XRD data. The superstructure reflections are highlighted in the inset.
References
1. Pan, H.; Zhang, S.; Chen, J.; Gao, M.; Liu, Y.; Zhu, T.; Jiang, Y., Molecular Systems Design & Engineering, 2018, 3, 748-803. 2. Shukla, A. K.; Ramasse, Q. M.; Ophus, C.; Duncan, H.; Hage, F.; Chen, G., Nature Communications, 2015, 6, 8711. 3. Yu, H.; Ishikawa, R.; So, Y.-G.; Shibata, N.; Kudo, T.; Zhou, H.; Ikuhara, Y., Angewandte Chemie International Edition, 2013, 52.23, 5969-5973.
Session 5: 11:00 - 11:15
Tunability of sodium-metal-sulfate frameworks for applications in Na-ion batteries
Laura L. Driscoll,1 Elizabeth H. Driscoll1 and Peter R. Slater.1 1 School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT
With the imperative need to incorporate more renewable power sources into the grid to meet emission targets, large scale energy storage will need to play an increasingly important role in order to supplement the grid during peak times (when such sources may not be readily available). Li-ion is unrivalled in energy density and is the dominant technology used in numerous applications; however, it is rare to find such batteries in large scale grid storage, largely due to the cost of Li. Li and Na possess similar chemistries and the latter is far more abundant and inexpensive, an invaluable advantage for large scale storage as these systems are likely to be stationary, where the £/Wh becomes a more important factor than Wh/kg. In order to maximise the cells performance, there is a lot of interest in sulfate systems, as these systems should possess the highest cell voltages due to the inductive effect.
In this talk, we will discuss how doping of the hydrated precursor (Na2M(SO4)2·H2O) can yield different phases on dehydration. The resultant phase was shown to be dependent on the level of dopant and the transition metal selected to form the framework. Although the initial study focused on substitution of the oxyanion unit (yielding alluaudite type - Na3M1.5(SO4)1.5(SeO4)1.5), trends that were observed during this study were later applied to transition metal doping which enabled stabilization of Na2(Fe/Ni)(SO4)2.1–3 The flexibility of these systems towards doping can allow for fine tuning of the material’s electrochemical properties.
References
1 L. L. Driscoll, E. Kendrick, A. J. Wright and P. R. Slater, J. Solid State Chem., 2016, 242, 103–111.
2 L. L. Driscoll, E. Kendrick, K. S. Knight, A. J. Wright and P. R. Slater, J. Solid State Chem., 2018, 258, 64–71.
3 E. H. Driscoll, L. L. Driscoll and P. R. Slater, J. Solid State Chem., 2020, 282, 121080.
Figure 1. Crystal structures of Na2M(SO4)2 (left) and Na2+xM2-x(SO4)3 (Right)
Session 5: 11:15 - 11:30
Session 611:45 - 12:45
Ionic conduction in disordered hexagonal perovskite derivatives
Sacha Fop1 and Abbie C. Mclaughlin 1. 1 Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
Interest in proton and oxide ion conducting materials has recently risen due to their application as electrolytes in energy-related technologies, such as proton ceramic fuel cells (PCFCs) and solid oxide fuel cells (SOFCs). 1 Fluorite and cubic perovskite compounds have dominated this research field, although the search for electrolytes able to operate at intermediate temperatures (300 – 600 °C) has led to the discovery of high ionic conductivity in other structural families. 2 We have explored the family of hexagonal perovskites and have recently identified significant ionic conductivity in some cation-deficient derivatives displaying considerable cation and anion disorder. 3, 4 Here we report on Ba7Nb4MoO20, which presents a hybrid average structure composed by palmierite-like layers alternated with 12R hexagonal perovskite units (Figure 1). Oxygen disorder within the palmierite-like layers leads to the formation of local variable coordination environments (4-, 5-, 6-fold), while the random arrangement of cationic vacancies results in complex stacking configurations. 4 This system uptakes a significant amount of water and exhibits high proton and oxide ion conductivity. Preliminary results from in situ neutron diffraction experiments under controlled dry/humidified atmosphere reveal the mechanism of hydration and highlight the importance of the absorbed water molecules in inducing the structural disorder. Bond valence sum energy (BVSE) and atomistic calculations provide information regarding the possible proton locations and ionic migration pathways. These findings are valuable in developing strategies to further improve the conductivity of this class of materials.
Figure 1. Average crystal structure of Ba7Nb4MoO20, showing the stacking of palmierite (P) and hexagonal perovskite (12R) layers.
References 1 C. Duan et al, Science, 2015, 349, 1321 2 L. Malavasi, C. A. Fisher and M. S. Islam, Chem. Soc. Rev., 2010, 39, 4370. 3 S. Fop, K. S. McCombie. R. I. Smith and A. C. Mclaughlin, Chem. Mater., 2020, 32, 4724. 4 S. Fop et al, Nat. Mater., 2020, 19, 752. 5 S. Fop et al, manuscript in preparation.
Session 6: 11:45 - 12:00
Influence of Structural Changes on Sodium Storage Mechanism and Electrochemical Performance in Hard Carbons for Sodium ion Batteries
Hande Alptekin,1 Heather Au1 Anders Jensen2, Alan Drew2and Maria-Magdalena Titirici.1 1 Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK,
2 School of Physics and Astronomy and Materials Science and Materials Research Institute, Queen Mary University of London, London E14 NS, UK,
Inexpensive, efficient energy storage systems are essential for the wide-scale successful implementation of renewable energy technologies. Among the various available energy storage technologies, Li-ion batteries (LIB) have been have received considerable attention. However, in terms of largescale application they are not suitable because their price is very high, which is resulting from the uneven distribution of lithium reserve around the world and increasing consumption. Hence, it is crucial to research low-cost secondary batteries for energy storage technologies. Sodium is located below Li in the periodic table, so it possesses similar chemical and physical properties to Li in many aspects. First of all, regarding availability sodium is fourth most abundant element in the Earth’s crust, making sodium relatively inexpensive. Namely, sodium-based batteries could provide an alternative chemistry to lithium batteries and might become competitive to lithium-ion batteries. However, there are still inevitable drawbacks related to discovery of suitable anode materials. Optimizing the porous and graphitic structure of the anode materials is important to achieve electrochemically elevated Na-ion battery technology.
In this study, we will present the preparation of a series of hard carbon anode materials prepared via the Hydrothermal Carbonisation (HTC) followed by high temperature carbonisation. Applying various carbonization temperatures results in carbon materials with different pore morphologies, functional groups and graphitisation degrees which were characterised by HRTEM, XPS, Raman, SAXS/WAXS, total neutron scattering, NMR and in-situ electrochemical dilatometry. The influence of material morphology, degree of graphitisation, pore structure, particle size and defects on electrochemical performance and Na-storage mechanism were investigated. Being able to design and modify the electrode structure and chemistry allowing us to move closer to electrochemically optimized, high performance and efficient Na ion batteries.
Session 6: 12:00 - 12:15
Zn2-averievite: a new quantum spin liquid candidate
Georgopoulou M.1, Fak B.1, Boldrin D.2, Wills A.S.3
1Institut Laue-Langevin, Grenoble, France, 2School of Physics and Astronomy, University of Glasgow, Glasgow, UK,
3Department of Chemistry, University College London, London, UK.
Quantum spin liquids (QSLs) are novel states of matter that display exotic ground states and fractionalized excitations as a consequence of many-body entanglement.1,2 Unlike conventional magnetically ordered systems, QSLs have no broken symmetry nor any Landau-type order parameters and show no long-range magnetic order down to 0 K. Their quantum states, described by complex wave-functions, are better characterised using projective symmetry groups.3 In two dimensions, the most promising model system is the S = 1/2 kagome Heisenberg antiferromagnet (KHAF), where quantum spins form a geometrically frustrated network of corner-sharing triangles known as the kagome lattice.
Despite the importance of this system, good experimental examples remain rare. The best example, if not the only, is the mineral herbertsmithite, γ-ZnCu3(OD)6Cl2. Unfortunately, herbertsmithite is plagued by Cu/Zn inter-site mixing, which prevents the determination of whether the continuum of fractional spin excitations observed by inelastic neutron scattering is gapped or not.4-6
We would like to present our findings on the averievite series, ZnxCu5-x(VO4)2O2CsCl for x=0, 1 and 2, where the x=2 member is the KHAF. Averievite is an oxide material containing a Cu2+ pyrochlore slab structure, reminiscent of clinoatacamite, where the slab layers are well separated by ZnVO3 and CsO2 groups (Figure 1a).7 In agreement with the literature, our x=0 sample shows antiferromagnetic ordering below 22 K with dominant antiferromagnetic interactions. Dc magnetometry shows our x=2 sample has no long-range magnetic order down to 2 K and our inelastic neutron scattering experiments on IN5 at 1.5 K show diffuse excitations (Figure 1b), reminiscent of what theory predicts for QSLs.
References 1 L. Balents, Nature, 2010, 464, 199. 2 L. Savary and L. Balents, Rep. Prog. Phys., 2017, 80, 016502. 3 X.-G. Wen, Phys. Rev. B, 2002, 65, 165113. 4 T.H. Han, J.S. Helton, S. Chu, D.G. Nocera, J.A. Rodriguez-Rivera, C. Broholm and Y. Lee, Nature, 2012, 492, 406. 5 M. Fu, T. Imai, T. Han and Y. Lee, Science, 2015, 350, 655. 6 P. Khuntia, M. Velazquez, Q. Barthélemy, F. Bert, E. Kermarrec, A. Legros, B. Bernu, L. Messio, A. Zorko and P. Mendels, Nat. Phys., 2020, 16, 469. 7 A. S. Botana, H. Zheng, S. H. Lapidus, J. F. Mitchell and M. R. Norman, Phys. Rev. B, 2018, 98, 054421.
x
y z
Cs
Cl
V O
Cu
Zn
E (m
eV)
Q (Å-1
)
a.
b.
Figure 1: (a) Crystal structure of Zn2Cu3(VO4)2O2CsCl. (b) Zn2Cu3(VO4)2O2CsCl dynamic structure factor, S(Q,E), as a function of energy, E, and momentum transfer, Q, at 1.5 K.
S(Q
, E) (
arb.
uni
ts)
Session 6: 12:15 - 12:30
Engineering nanowires of high-temperature superconductors
Emily Luke,1,2 Hector Christodoulou2, Jason Potticary1,2 and Simon R. Hall.1,2 1 The Bristol Centre for Functional Nanomaterials, University of Bristol, BS8 1FD, UK b
2 Complex Functional Materials Group, School of Chemistry, University of Bristol, BS8 1TS, UK
The frequency range of 0.1 to 2 THz is currently relatively unexplored due to a lack of solid-state devices that can produce these frequencies. This is known as the terahertz gap. A material with the potential to bridge this gap is the high-temperature superconductor, Bi2Sr2CaCu2O8+x (BSCCO).1 This is due to the potential exploitation of the Josephson effect, which allows the emission of radiation from a Josephson Junction (JJ). As the emission from a single junction is weak, a high density of JJs must emit coherently to produce an appreciable signal. The crystal structure of BSCCO intrinsically contains JJs in between the superconducting copper oxide planes. The space between these JJs is only 1.5 nm, meaning that a single crystal of the sample accommodates a high density of JJs with the capacity to emit coherently.
In this work, we have produced nanowires of BSCCO by exploiting the previously reported micro-crucible mechanism in a solid-state synthesis.3 The material was shown to exhibit a superconducting transition temperature of 79 K from SQUID magnetometry, and purity was assessed using powder X-ray analysis, energy-dispersive X-ray analysis and electron diffraction.
References 1 L. Ozyuzer, A. E. Koshelev, C. Kurter, N. Gopalsami, Q. Li, M. Tachiki, K. Kadowaki, T. Yamamoto, H. Minami, H. Yamaguchi, T. Tachiki, K. E. Gray, W.-K. Kwok and U. Welp, Science, 2007, 318, 1291–1293. 2 R. Kleiner and H. Wang, J. Appl. Phys., 2019, 126, 171101. 3 R. Boston, Z. Schnepp, Y. Nemoto, Y. Sakka and S. R. Hall, Science, 2014, 344, 623–626.
2 µm
Session 6: 12:30 - 12:45
Session 713:15 - 14:30
‘Baking a Battery’ – an educational resource to explain battery manufacturing
Sophia Constantinou1,2, Elizabeth Driscoll3, Emma Kendrick4 and Peter Slater3
1 School of Chemistry, The University of Edinburgh, Joseph Black Building, EH9 3FJ 2 The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 0RA, UK
3 School of Chemistry, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK 4 School of Metallurgy and Materials, The University of Birmingham, Edgbaston, B15 2TT, UK
Limited educational resources are available to explain rechargeable battery operation, in particular Li-ion batteries, and often the scientific topics underpinning this technology, such as electrochemistry, are found to be quite challenging for students to grasp.1 With a research field now under the public spotlight due to the increased interest in electric vehicles, it is paramount this technology, which is already widely used in society (within the portable electronics industry) can be appreciated by users in terms of the efforts and challenges researchers face, in particular the ability to up-scale and manufacture these batteries for commercial use.
To support these resources, it is important to also consider educational literature, where the importance of meaningful learning (rather than rote learning) is detailed. Novak’s theory of education, known as Human Constructivism, states that “meaningful learning underlies the constructive integration of thinking, feeling, and acting, leading to human empowerment for commitment and responsibility.”2 With these concepts in mind, educational resources were designed to fit in with these principles: bringing battery science into the context of our everyday lives and using an analogy to relate an unfamiliar concept to a familiar one. The resources were also designed to build upon the recent resource of ‘battery jenga’ created by Driscoll et al. which aids and explains how this type of battery works.3
The overall aims for this project have been to inspire the next generation of battery scientists and make the science of battery manufacturing more accessible to science students and to non-scientific audiences.
Figure 1: Infographic using the cake analogy to explain the components of a battery
1 Özkaya, A. R. Conceptual Difficulties Experienced by Prospective Teachers in Electrochemistry: Half-Cell Potential, Cell Potential, and Chemical and Electrochemical Equilibrium in Galvanic Cells. J. Chem. Educ. 2002, 79 (6), 735– 738, DOI: 10.1021/ed079p735
2 S. Lowery Bretz, Novak’s Theory of Education: Human Constructivism and Meaningful Learning, 2001, vol. 78.
3 E. H. Driscoll, E. C. Hayward, R. Patchett, P. A. Anderson and P. R. Slater, Journal of Chemical Education (2020), DOI:10.1021/acs.jchemed.0c00282.
Session 7: 13:45 - 13:55
NanoWOW: Materials Science for Kids
Annie Regan,1 and Dr. Rachel Kavanagh.2 1 CDT ACM, AMBER, Trinity College Dublin, Dublin 2, Ireland
2 AMBER, Trinity College Dublin, Dublin 2, Ireland.
NanoWOW is a primary science education programme designed by AMBER, the Science Foundation Ireland centre for Advanced Materials and BioEngineering Research. Developed for children between 10-12 years old, the NanoWOW programme is composed of short educational videos, experiments, PowerPoints, and learning activities – covering the basics of materials science for any young, budding scientist. The programme initially began as a free pack that primary school teachers could avail of to introduce the world of nano and materials science to 5th and 6th class students in 2014.1 However, since the COVID-19 global pandemic the programme has been tailored and made accessible to parents and teachers alike, bringing science education to the home learning environment. By 21st May 2020, five new videos with complimentary resources were added to the NanoWOW pack; presented by AMBER research scientists who introduced the concepts of material properties, scale and surface area, 3D and 2D structures, the future of nanoscience, and nanoscience in nature.2 This short talk aims to delve into the origins of the NanoWOW programme and take you through its journey towards being an accessible tool for the home learning environment. The results of a comprehensive communication and education strategy for NanoWOW will be presented, while drawing from first-hand experience as one of the presenters. With 1,400 unique viewers for all five videos, and 450 resource downloads, this talk aims to give insight into the possibilities and pitfalls of online science communication, education and evaluation in the time of COVID.
Figure 1: AMBER’s NanoWOW Branding
References 1 Seomra Ranga, https://www.seomraranga.com/2013/12/nano-wow-an-introduction-to-nanoscience/, (accessed August 2020) 2 AMBER Centre, http://ambercentre.ie/nanowow/#videos, (accessed August 2020).
Session 7: 13:55 - 14:05
Development of new battery education resources for use in schools;
Explaining battery recycling methods and use of LiFePO4 as an electrode material
Emily Hanover1,2, Elizabeth Driscoll1 , Emma Kendrick3 and Peter Slater1 1 School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
2 The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 0RA, UK 3 School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT, UK
Lithium-ion batteries (LiBs) are all around us; whether it be in your phone, your laptop or even your brand new electric car. There is no way to escape them. Despite this, the inner workings of these batteries are less well discussed to the wider non-scientific audiences. With this in mind, resources have been produced to supplement the teaching of this topic in association with The Faraday Institution.
In this presentation, I will present two of the several resources I have produced during my internship. The first is a development on the already acclaimed ‘Battery Jenga’1. Where the original presents the use of LiCoO2 and graphite as electrodes, the newly produced version presents LiFePO4 as an alternative transition metal oxide electrode. Supplementary cards, produced during the project, catering for GCSE and A Level students, have been produced.
The second resource developed is based on the children’s game; ‘Operation’, where the original game’s concept has been adapted to demonstrate disassembling a LiB found in an electric car. This game will be part of a workshop aimed at KS3 students introducing recycling of batteries.
The overall goal has been to design useable resources that can be utilised within a classroom, either by a teacher or a visitor, to develop student’s understanding further in this topic. I will present these resources and the produces involved in their development.
Figure 1; A tactile Jenga set arranged to show a simplified arrangement of LiFePO4 olivine crystal structure (left) and a graphite cell has been produced. The tactile nature allows students who live with visual impairment to access the set.
Figure 2; Image of ‘Disassembly of a battery’ game, based on ‘Operation’, shows the battery cover and the button to turn the buzzer on.
Figure 3; Battery game with cover removed, which shows the Battery Management System (BMS), the Power electronics, wires and modules. One module has been manufactured to show an example of cells within the battery.
References 1 E. H. Driscoll, E. C. Hayward, R. Patchett, P. A. Anderson, and P. R. Slater, J. Chem. Educ., 2020, 97 (8), 2231–2237.
Fig. 1 Fig. 2 Fig. 3
Session 7: 14:05 - 14:15
Outreach Q&A Panel
14:15 - 14:30
Prizes &
Closing14:30
