Combined synthesis and computational search for new correlated electronic materials

Worldwide efforts are being made to develop new transition metal oxides due to their wide array of interesting behaviours such as superconductivity, magnetoresistance, ferroelectricity, photoluminescence, thermoelectricity, etc. More specifically, perovskites oxides, having the general ABO3 structure with large B cations sitting inside a framework of A cations and oxygen ions, have the ability and flexibility to accommodate a large variety of elements and are thus widely studied in order to carefully design new functional materials. A library of these oxides is built up generally by the substitution of cations. However, the anion or oxide chemistry can be vastly expanded through changes in the anionic lattice which is difficult to accomplish through conventional thermodynamic synthesis as only the most stable configuration or a mixture of configurations is formed. The varying stoichiometries of anions can be explored through kinetic control with topochemical reactions, which are reactions that are locally confined with crystal lattices. For example, the reduction of LaSrNiRuO6 to LaSrNiRuO4 leads to the formation of novel Ru2+ centers, allowing its electronic structure to be studied in extended oxide frameworks. It is, however, time-consuming to explore the chemical space of perovskite oxides through experimentation only.

Recently, a wide range of functional materials have been under study by machine learning, allowing the exploration of vast configuration landscapes with high efficiency. For instance, machine learning has been applied to aid materials discovery such as the prediction of the critical temperature of superconducting materials, Curie temperature of ferromagnets, electronic structure features of photovoltaics, etc. While computational methods have been used to study topochemically modified structures, their simulations involve solving complex quantum mechanical equations, requiring exponentially increasing computational power with system size. Therefore, simulating numerous systems with a large number of atoms to elucidate material behaviour is extremely difficult with conventional methods. This project aims to combine computational modelling including machine learning and synthesis to expedite the discovery of these new topochemically altered perovskite oxides. Ultimately, this will provide an opportunity to create a feedback loop in which a new material is predicted by machine learning from existing databases, synthesising the material and feeding the information back to the learning model allowing the exploration of a myriad of material structures.
This project falls within the EPSRC Functional Ceramics and Inorganics research area.

The primary impact of the OxICFM CDT will be the highly-trained world-class scientists that it delivers. This impact will encompass both the short term (during their doctoral studies), the medium term (subsequent employment) and ultimately the longer timescale defined by their future careers and consequent impact on science, engineering and policy in the UK.

The impact of OxICFM students during their doctoral studies will be measured by the culture change in graduate training that the Centre brings about - in working at the interface between inorganic synthesis and manufacturing, and fostering cross-sector industry/academia working practices. By embedding not only from larger companies, but also SMEs, we have developed a training regime that has broader relevance across the sector, and the potential for building bridges by fostering new collaborations spanning enormous diversity in scientific focus and scale. Moreover, at a broader level, OxICFM offers to play a unique role as a major focus (and advocate) for manufacturing engagement with academic inorganic synthetic science in the UK.

From a scientific perspective, OxICFM will be uniquely able to offer a broad training programme incorporating innovative and challenging collaborative projects spanning all aspects of fundamental and applied inorganic synthesis, both molecular and materials based (40+ faculty). These will address key challenges in areas such as energy provision/storage, catalysis, and resource provision/renewal necessary to enhance the capability and durability of UK plc in the medium term. To give some idea of perspective, the output from previous CDTs in Oxford's MPLS Division include two start-up companies and in excess of 30 patents.

It is not only in the industrial and scientific realms that students will have impact during their timeframe of their doctorate. Part of the training programme will be in public engagement: team-based challenges in resource development/training and outreach exercises/implementation will form part of the annual summer school. These in turn will constitute a key part of the impact derived from the CDT by its engagement with the public - both face-to-face and through electronic/web-based media. As the centre matures, our aspiration is that our students - from diverse backgrounds - will act as ambassadors for the programme and promote even higher levels of inclusion from all parts of society.

For our partners, and businesses both large and small in the manufacturing sector, it will be our students who are considered the ultimate output of the OxICFM CDT. Our programme has been shaped by the need of such companies (frequently expressed in preliminary discussions) to recruit doctoral graduates who can apply themselves to a broad spectrum of multi-disciplinary challenges in manufacturing-related synthesis. OxICFM's cohort-based training programme integrates significant industry-led training components and has been designed to deliver a much broader skill set than standard PhD schemes. The current lack of CDT training at the interface of inorganic chemistry and manufacturing (and the relevance of inorganic molecules/materials to numerous industrial sectors) heightens the need for - and the potential impact of - the OxICFM CDT. Our students will represent a tangible and valuable asset to meet the long-term skills demand for scientists to develop new materials and nanotechnology identified in the UK Government's 2013 Foresight report.

In the longer term, the broad and relevant training delivered by OxICFM, and the uniquely wide perspective of the manufacturing sector it will deliver, will allow our graduates to obtain (and thrive in) positions of significant responsibility in industry and in research facilities/institutes. Ultimately we believe that many will go on to be future research leaders, driving innovation and changing research culture, and thereby making a lasting contribution to the UK economy.