Chemistry is at the heart of many of the great technological transformations of the modern era. The urgent transition away from energy-dense but environmentally-damaging fossil fuels presents a new grand challenge for chemistry, centred on the design of materials associated with the conversion, distribution and utilisation of energy. In particular, the rapid expansion of solar and wind power will necessitate the use of large-scale energy storage, spanning wide ranges of energy, power and storage duration in diverse applications including domestic power, transportation and grid management. In order to meet this challenge, we must leverage existing technology while simultaneously developing new materials with enhanced properties. The research programme contained within this Fellowship application details a plan to develop a new family of inorganic metal-nitrogen-hydrogen (M-N-H) materials, with an emphasis on their application to sustainable energy storage. At the core of this project is a synthetic programme which aims to significantly expand the range of M-N-H materials, moving beyond these first examples to systems which display a wider range chemical bonding types and metals. Consideration of the application of M-N-H materials has been largely restricted to the Group I and II metal amides and imides (NH2- and NH2- bearing inorganic salts) in the context of lightweight hydrogen storage materials. More recently, these same materials have been identified as effective ammonia decomposition catalysts, and have been implicated in the enhanced ammonia synthesis activity of hydride-based composite catalysts. Ammonia is increasingly considered as a viable high energy density fuel and hydrogen carrier, and the catalytic activity of M-N-H materials may help promote its use. One theme of this fellowship will therefore be the expansion of the relatively small number of materials have been tested for their catalytic activity. Screening of the new M-N-H materials would not only result in the development of more active catalysts, but also a more complete understanding of the properties which govern their catalytic action. Many functional materials are based on oxides, and property variation comes from varying the array of cations in the oxide material. Imide anions are similar to oxide, and so offer a path to creating analogous materials. For example, lithium oxide and lithium imide are isostructural, yet lithium imide shows ionic conductivity which is dramatically enhanced compared to the oxide. This part of the programme will seek to elucidate the relationship between imides and oxides, and to use this principle as a guide for the design of new imide-based functional materials. In particular, synthesis of imides with high ionic conductivity and electrochemically-active components (e.g. cathode materials) will be pursued with the goal of developing a concept imide battery material. The aim is to provide new insights into the fundamental chemistry of the M-N-H family and illustrate new approaches for the design of energy storage materials.

The Scottish Doctoral Training Centre in Condensed Matter Physics, known as the CM-DTC, is an EPSRC-funded Centre for Doctoral Training (CDT) addressing the broad field of Condensed Matter Physics (CMP). CMP is a core discipline that underpins many other areas of science, and is one of the Priority Areas for this CDT call. Renewal funding for the CM-DTC will allow five more annual cohorts of PhD students to be recruited, trained and released onto the market. They will be highly educated professionals with a knowledge of the field, in depth and in breadth, that will equip them for future leadership in a variety of academic and industrial careers. Condensed Matter Physics research impacts on many other fields of science including engineering, biophysics, photonics, chemistry, and materials science. It is a significant engine for innovation and drives new technologies. Recent examples include the use of liquid crystals for displays including flat-screen and 3D television, and the use of solid-state or polymeric LEDs for power-saving high-illumination lighting systems. Future examples may involve harnessing the potential of graphene (the world's thinnest and strongest sheet-like material), or the creation of exotic low-temperature materials whose properties may enable the design of radically new types of (quantum) computer with which to solve some of the hardest problems of mathematics. The UK's continued ability to deliver transformative technologies of this character requires highly trained CMP researchers such as those the Centre will produce. The proposed training approach is built on a strong framework of taught lecture courses, with core components and a wide choice of electives. This spans the first two years so that PhD research begins alongside the coursework from the outset. It is complemented by hands-on training in areas such as computer-intensive physics and instrument building (including workshop skills and 3D printing). Some lecture courses are delivered in residential schools but most are videoconferenced live, using the well-established infrastructure of SUPA (the Scottish Universities Physics Alliance). Students meet face to face frequently, often for more than one day, at cohort-building events that emphasise teamwork in science, outreach, transferable skills and careers training. National demand for our graduates is demonstrated by the large number of companies and organisations who have chosen to be formally affiliated with our CDT as Industrial Associates. The range of sectors spanned by these Associates is notable. Some, such as e2v and Oxford Instruments, are scientific consultancies and manufacturers of scientific equipment, whom one would expect to be among our core stakeholders. Less obviously, the list also represents scientific publishers, software houses, companies small and large from the energy sector, large multinationals such as Solvay-Rhodia and Siemens, and finance and patent law firms. This demonstrates a key attraction of our graduates: their high levels of core skills, and a hands-on approach to problem solving. These impart a discipline-hopping ability which more focussed training for specific sectors can complement, but not replace. This breadth is prized by employers in a fast-changing environment where years of vocational training can sometimes be undermined very rapidly by unexpected innovation in an apparently unrelated sector. As the UK builds its technological future by funding new CDTs across a range of priority areas, it is vital to include some that focus on core discipline skills, specifically Condensed Matter Physics, rather than the interdisciplinary or semi-vocational training that features in many other CDTs. As well as complementing those important activities today, our highly trained PhD graduates will be equipped to lay the foundations for the research fields (and perhaps some of the industrial sectors) of tomorrow.

This fellowship is situated at the interdisciplinary boundary of chemistry, physics and crystallography and will deliver transformative insights into the crystal structure-functional property relationships in next-generation advanced materials. Advanced functional and quantum materials are an exciting frontier in current research. They are widely studied due to the intriguing properties they host such as ferroelectricity, multiferroicity, quantum magnetism and spin liquid phases. A number of them form a major part of our daily technology, ubiquitous in applications as wide ranging as touchscreens, loudspeakers in smartphones and sensors in medical ultrasound devices. At the cutting edge of materials discovery, compounds are becoming ever more complex in structure, with new mechanisms driving their properties. To enable further targeted development and rational design, it is paramount to understand the microscopic structure-property relationships in these current materials in order to develop design pathways for the next generation of advanced materials. However, these complex materials pose two key challenges to traditional approaches to studying these - complexity and sensitivity. Their complexity makes it difficult to deduce the crystal structure with the required accuracy, even with advanced synchrotron, electron and neutron based techniques. The sensitivity of the properties to subtle details of the crystal structure as a function of e.g. chemical composition, temperature and magnetic field makes it extremely hard to correlate the (traditionally separate) determinations of structure and physical properties. Through this fellowship I will apply a transformative cross-disciplinary approach to tackle these problems, combining (i) state-of-the art neutron diffraction, (ii) targeted materials synthesis, (iii) unique in-situ physical property measurements and (iv) isotopic enrichment to unravel the highly non-trivial structure-property relationships in advanced materials. My expertise in chemistry, physics and crystallography, along with access to state-of-the-art facilities and collaborations with world-leading groups will drive this interdisciplinary research programme which will provide the foundations for tailored rational design of novel advanced materials. The focus is on two key scientific themes. The first is the exploration and discovery of crystal structure-physical property relationships in a new generation of complex ferroelectrics and multiferroics. These have wide-ranging potential applications from specialised sensors and actuators in automotive and aerospace applications to affordable, sustainable mass-market devices for consumer technology. The second research theme will concentrate on materials in which atomic-level quantum phenomena coupled with unique structural motifs give rise to novel emergent quantum phases. These include complex quantum magnetism in non-centrosymmetric materials and elusive quantum spin liquid phases.

Realization of new technologies that are able to minimize energy consumption and reduce our dependence on fossil fuels depends critically on the development of novel materials. For example, the most immediate obstacle to the widespread use ofhydrogen as a clean energy carrier is the practicality of hydrogen storage for on-board applications: no existing materials satisfy the required specifications. Superconductors can also have a major impact on numerous technologies in transportation, medicine, electronics etc., provided that they can operate at relatively high temperatures and carry significant current.I plan to explore an important class of materials, metal borides, that have a wide range of potential applications: superconductors, hydrogen stores, batteries, catalysts, and hard coatings. My main goal is to perform an extensive ab initio analysis of metal boride properties that will reveal binding mechanisms across a wide range of structures and compositions. I will use the acquired fundamental knowledge to develop an efficient compound prediction method - a new method is required because the complexity of metal borides' morphologies prohibits the use of automated compound prediction methods recently developed for metal alloys. Development of such a tool will speed up the design of multi-component metal borides for specific applications.I have already attempted to use this strategy for rational materials design during my postdoctoral work and demonstrated its effectiveness on particular examples. I have revisited a few selected binary and ternary metal-boron systems and identified several previously overlooked promising candidate compounds with appealing properties. This gives grounds for optimism that a more large-scale systematic search for stable phases will reveal new materials of great practical importance. My main focus will be on metal borides with potential for superconductivity or hydrogen storage, as I have expertise in these fields. As part of my career development I also plan to extend my research to other areas, such as battery applications. I believe that consideration of such a broad range of applications in one combined study is not only a sensible but also the most efficient work plan. Indeed, as described in the proposal, metal borides with very different properties may have an underlying structural link and their stability regions can be investigated investigated in one set of carefully planned simulations and experiments.

In optimizing the properties of functional materials it is essential to understand in detail how structure influences properties. Identification of the most important structural parameters is time-consuming and usually investigated by preparing many different chemical modifications of a material, determining their crystal structures, measuring their physical properties and then looking for structure-property correlations. It is also necessary to assume that the chemical modifications have no influence other than to distort the structure, which is often not the case. High pressure offers a way around these difficulties. Pressure can be used to distort a material without the need for chemical modification. Both crystal structures and physical property measurements can be conducted at high pressure, so that the properties of the same material can be studied in different states of distortion, providing the most direct way to study correlations between structure and properties. In this proposal we focus on structure-property relationships in molecule-based magnets connected into extended chains, networks or frameworks using a combination of high pressure crystallography, magnetic measurements, spectroscopy and simulation which will exploit the UK's unique capabilities in extreme conditions research. Extended materials are of great interest because a small distortion at one site is propagated throughout the material by the strong chemical links between the magnetic centres, making the magnetic properties very sensitive to structural changes. We will design and build new instruments for magnetic susceptibility and diffraction measurements at high pressure and low temperature and we will exploit these new instruments and methodology to study two important classes of magnetic material. 1-D magnetic materials represent a fertile playground for discovering and understanding exotic physical phenomena. The magnetic behaviour of Single-Chain Magnets (SCMs) is fundamentally governed by the magnitude of nearest neighbour exchange interactions (intra-chain exchange), the extent of inter-chain interactions, and Ising-like anisotropy - all of which are sensitive to pressure. We have already shown that these parameters can be pressure-tuned in Single-Molecule Magnets (SMMs) and the same should be true for SCMs In 3-D frameworks magnetism can be combined with porosity, so that inclusion of different guest molecules provides another means for controlling magnetic properties. Prussian Blue Analogues consist of different metal cations linked by cyanide anions, while metal carboxylates build diamond-like frameworks. In both cases guest molecules influence magnetic ordering temperatures. Some metal-organic frameworks show spin-crossover behaviour, where different electronic configurations of the metal ions are stable under different conditions. The transition from one form to another is influenced by guest molecules which occupy the pores of the framework. High pressure will enable us to control the structure of the framework itself, the interactions between the host and the guest, and the number of guest molecules incorporated into the pores, providing a quantitative link between host-guest interactions and magnetism.