This program is about using nanostructured materials to address key areas in energy related applications. This proposal will deliver world class materials science through ambitious thin and thick film development and analysis and the proposal targets the EPSRC strategic areas Energy and Nanoscience through nanoengineering. The programme grant will provide the opportunity to integrate three well established research areas that currently operate independently of each other and will establish a new consortium of activities. Collectively they offer the essential ingredients to move this particular field forward. The planned program of work is timely because of the convergence of modelling capability, precision multilayer oxide growth expertise and nanofabrication facilities. The overall vision for the Programme Grant is focussed on Energy. Within the Programme we aim to find means of reducing energy consumption for example by using electro and magnetocaloric means of cooling; generating energy by use of nanoscale rectifying antennas and finally storing energy by photocatalytic splitting of hydrogen from water. Our program is divided into two themed areas:1) Nanostructured oxides for Energy Efficient Refrigeration with 2 project areasElectrocaloricsMagnetocalorics2) Nanostructured oxides for energy production and storage with 2 project areasSolar HarvestingPhotocatalysisThis research will enable :- The development of new materials, new material architectures and new device concepts for energy refrigeration and energy harvesting. The synergy across a range of programs particularly the underpinning activities of materials theory, modelling and characterisation will move these important fields closer to application.- The research will also enable a new forum to be established, with representation from UK and European scientists and industrialists so that broad discussions can be held to enable moving these fields forward. We place a significant emphasis on training, outreach and knowledge transfer.The research challenges that need to be addressed are:- Designing physical systems that are close to an instability so that small external perturbations from magnetic or electric fields, optical or thermal excitation will tip the system into a new ground state- Optimising control over (strain, defects, doping inhomogeneity, disorder) and first layer effects in thin film oxides (with thicknesses of the order of 10nm or less) so that we can develop the capability to tune the band gap of the oxide using directed modelling and targeted growth control.

Although it is one of the most prosaic properties of a material, the response to an applied electrical voltage can be one of its most profound. Initial insight into why some materials are electrical conductors while others are insulators came from the early application of quantum mechanics. In this view, electrons in "simple" materials are treated as independent, and solids are classified according to the number of electrons filling the quantum states: for an even number the states are filled, resulting in an insulator, whereas for an odd number the states are partly filled allowing the electrons to conduct. Although this rule of thumb works for many "simple" materials, including e.g. aluminum and silicon on which a large fraction of our current technologies are based, it fails spectacularly for others. Simple oxides of transition metals, for example, exist with partially filled electron states. Mott first proposed that it was only by including electron interactions, which in materials such as oxides can be dominant, that the metal-insulator transition can be understood. Hubbard later proposed a deceptively simple model with just two parameters, describing the tendency of electrons either to localize (insulating behaviour) or delocalize (metallic). For more than 50 years, the Mott-Hubbard paradigm has provided the abiding theoretical framework for rationalizing the electronic and magnetic properties of "complex" quantum solids defined as those that exhibit explicit collective quantum effects, such as high-temperature superconductivity. More recently, the relativistic coupling of an electron's intrinsic spin with its orbital motion - the spin-orbit interaction (SOI) - has come sharply into focus with the discovery that it can lead to qualitatively new types of electronic state. It has been shown that even for certain "simple" materials the SOI leads to surface metallic states on materials that in the bulk are insulating. These surface states are non-trivial, in that they are protected by symmetries - or topology - and therefore cannot be easily destroyed. The question then naturally arises as to the consequences of including relativistic effects in "complex" quantum materials in which the electrons interact strongly. The answer requires developing a new paradigm - beyond the Mott-Hubbard one - that treats interactions and the SOI on an equal footing. This proposal is to perform experiments that will be key to establishing this new paradigm. This new frontier has attracted considerable theoretical attention, and a plethora of predictions have been made for exotic electronic and magnetic states, some of which in the long run may lead to new technologies. Examples include novel types of insulators, metals, superconductors, quantum spin liquids, etc. However, history shows that although theory provides a useful guide, it cannot anticipate all possibilities, and many exciting discoveries will no doubt be made through experimentation. Revealing the nature of the electronic and magnetic correlations in complex "quantum matter" through experimentation is very challenging, requiring techniques with extremely high sensitivity and specificity. A major theme of this proposal is the development of novel X-ray techniques which will offer unprecedented insights into the atomic scale order and excitations in solids. The techniques will be developed at large-scale central facilities, both nationally and internationally, which have dedicated particle accelerators for producing ultra intense X-ray beams. The recent advent of X-ray laser sources represent the pinnacle of this technology which deliver 20 orders of magnitude higher intensity than conventional sources in femto-second pulses (i.e. the time taken for light to transit a molecule). These sources are transformational enabling novel non-equilibrium electronic and magnetic states to be created and their evolution to be studied in real-time.

The ability to generate strong and stable magnetic fields is a critical enabling technology for a broad range of sustainable engineering applications. Almost invariably, more compact field sources and higher magnetic field densities lead directly to more efficient and cost effective devices. One example of this can be found in the widespread applications of small, high power DC electric motors, which have proliferated since the development of the cheap high energy density family of NdFeB materials in the 1980s. Wire-wound superconducting magnets, on the other hand, may offer the potential to generate large magnetic fields, but they are extremely expensive and are difficult to manufacture. A cheaper, simpler and more robust option is the use of magnetised bulk superconductors. The (RE)BCO (where RE = rare earth element such as Y, Nd, Sm, Gd, etc.) family of bulk, melt processed high temperature superconductors (HTS), in particular, is the subject of extensive world-wide developmental research. Bulk HTS materials offer considerable potential to both improve the performance of existing devices that incorporate permanent magnets and to develop new, high field and sustainable energy storage applications, in particular. Indeed, these materials represent a direct link between the physical sciences and the development of sustainable applications in the energy needs sector that will be fundamental to growth of the UK economy in the short to medium term. A number of important scientific and technical challenges to the incorporation of (RE)BCO bulk superconducting materials into practical engineering applications remain. These include improving process efficiency, sample properties, yield, reducing the cost of raw materials, recycling, processing larger samples with conformal geometries, development of a practical magnetisation process and the development of bespoke cryogenic systems for specific applications. The main objective of this proposal is to address and overcome the critical aspects of these challenges to gain a fundamental understanding of the single grain growth process. This will enable the cost-effective processing of (RE)BCO materials with conformal geometries that will be fundamental to their application in a range of sustainable engineering devices within the energy sector and healthcare industry. Specific emphasis of the project will be placed on the development of an effective recycling process to enable a new secondary bulk sample source for low to medium field applications, the development of a novel multi-seeding technique for fabricating large samples of conformal geometry and the development of a novel fabrication process based on a graded composition to produce bulk samples with homogeneous superconducting properties throughout the bulk microstructure.