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.

This proposal asks for funding to construct a dilution refrigerator insert for the 17 T cryomagnet previously constructed with EPSRC funds (grant EP/G027161). This cryomagnet is currently being used at neutron scattering facilities throughout the European Economic Area, and is available for use by user groups unconnected with Birmingham, with any necessary support to be provided by us. With the dilution refrigerator insert, the cryomagnet will be able to cover a much larger range of desired experimental materials, without compromising the work that can already be done over the temperature range 2 K to 330 K. At present, this is the largest horizontal magnetic field available for use at any neutron scattering facility. Because small angle neutron scattering is of use to a large number of research communities, being able to move the cryomagnet around from facility to facility maximizes its utility, as it would not be in use full time at any one particular institution. At present, this equipment has been used, amongst other things, to study the fundamental properties of cuprate superconductors and iron-based superconductors and the effects of magnetic fields on colloidal suspensions of fd virus. We propose to use it to look for anticipated single Landau level effects brought about by high fields in bismuth, as well as flux lines in Pauli-limited superconductors and non-centrosymmetric superconductors, and quantum magnetic ordering. By extending the temperature range downwards by almost two orders of magnitude, we will be able to extend the research programme into a region where many emergent condensed matter phenomena occur. For instance, heavy fermion superconductors provide fascinating examples of unconventional superconducting phases arising from novel interactions. With the mK region accessible, the cryomagnet is well suited to the critical fields typical for these materials, so that most of their superconducting phase diagrams can be explored. This also makes it easier to investigate the effects of Pauli-limited superconductivity in heavy fermion and pnictide materials. In addition, this grant will support use of all of the cryomagnet's capabilities by both ourselves and other user groups. As an example, some of our collaborators are very interested in using the cryomagnet to extend studies of magnetic alignment of mesoscopic structures in suspension. We will also be commissioning the cryomagnet at several other facilities, including synchrotron sources, with necessary adaptations to be driven by our collaborators.

This proposal will develop a core laboratory that brings together the critical research tools for the characterisation of isolated and coupled spins in a well-managed hub: SPIN-Lab. This will be achieve through the upgrade of exiting tools together with the purchase of state-of-the art instruments to replace ageing or oversubscribed facilities. Therefore, we will implement a coherent vision centred on a combination of techniques that is not usually prioritised in a single institution, and that will be unique in the UK. Ultimately SPIN-Lab will be positioned as a leading national centre for magnetism research, supported by a research officer and managed by a board including members from Materials, Physics, Chemistry, Earth Sciences, Life Sciences and Chemical Engineering. The current user base is over 50 investigators, spanning three faculties, at Imperial alone, and we will work closely with London-based institutions via for example the London Centre for Nanotechnology. The facility will be open to external users who will amount to 20% of the usage. Key research tools include: (a) a state-of-the-art SQUID-based Quantum Design Magnetic Properties Measurement System (MPMS-3) that will perform ultra-high sensitivity magnetic measurements in a range of conditions such as under photoexcitation, at high pressure, and in alternating fields. (b) A state-of-the-art continuous wave electron paramagnetic resonance (EPR) spectrometer coupled with a laser. (c) Upgrades to ensure sustainability of existing tools by implementing cryogen-free operation, as well as extending functionality to include ferromagnetic resonance, magnetic force microscopy, solid-state nuclear magnetic resonance and low temperature Hall probe. Our research will initially be applied to the following grand challenges: (1) Engineering novel solutions: Plastic electronics, catalysis, batteries, solar fuels; (2) Health and well-being: Hyperthermia and magnetic sensing; (3) Leading the data revolution: Spintronics and the Maser; (4) Discovery and the natural world: Natural magnetism, photosynthesis, photochemistry.

Resistance is futile: lightbulbs and heaters aside, the majority of electronic components are at their most efficient when their electrical resistance is minimized. In the present climate, with energy sustainability regularly topping the international agenda, reducing the power lost in conducting devices or transmission lines is of worldwide importance. Research into the nature of novel conducting materials is hence vital to secure the global energy future.Superconductivity, the phenomenon of zero electrical resistance which occurs below a critical temperature in certain materials, remains inadequately explained. At present, these critical temperatures are typically very low, less than 140 Kelvin (-133 Celsius), but a more complete understanding of what causes the superconducting state to form could result in the design of materials that display superconductivity at the enhanced temperatures required for mass technological exploitation. Unfortunately, it is the very materials which are most likely to lead us to this end, the so-called unconventional superconductors, that are the least understood. In such materials, the superconducting state appears to be in competition with at least two other phases of matter: magnetism and normal, metallic conductivity. A delicate balance governs which is the dominant phase at low temperatures; the ground-state. By making slight adjustments to the composition of the materials or by applying moderate pressures certain interactions between the electrons in the compound can be strengthened at the expense of others causing the balance to tip in favour of a particular ground-state. The technicalities of how to do this are relatively well-known. What remains to be explained is why it happens, what it is that occurs at the vital tipping point where the superconductivity wins out over the magnetic or the metallic phases - in short, exactly what stabilizes the unconventional superconducting state? It is this question that the proposed project seeks to answer. I will use magnetic fields to explore the ground-states exhibited by three families of unconventional superconductor: the famous cuprate superconductors (whose discovery in the 1980s revolutionized the field of superconductivity and which remain the record-holders for the highest critical temperature); some recently discovered superconductors based on the most magnetic of atoms - iron (the discovery of these new materials in the spring of 2008 came as somewhat of a surprise, magnetism often being thought as competing with superconductivity); and a family of material based on superconducting layers of organic molecules. I propose to measure the strength of the interactions that are responsible for the magnetic and electronic properties of these materials as the systems are pushed, using applied pressure, through the tipping point at which the superconductivity becomes dominant. In particular, the electronic interactions in layered materials like those considered here can only be reliably and completely determined via a technique known as angle-dependent magnetoresistance. This technique remains to be applied to most unconventional superconductors, particularly at elevated pressures, mostly likely because it is experimentally challenging and familiar only to a handful of researchers. However, the rewards of performing such experiments are a far greater insight into what changes in interactions occur at the very edge of the superconducting state. Chasing the mechanism responsible for stabilizing unconventional superconductivity is an ambitious aim, and many traditional experimental techniques have proved inadquate. It is becoming clear, in the light of recent advances in the field, that the route to success lies in subjecting high-quality samples to the most extreme probes available, a combination of high magnetic fields and high applied pressures.

Magnetic Materials are employed in an enormous range of applications in modern society, from information storage in computers, refrigeration in security and astronomical instrumentation, biocompatible agents for use as both contrast and polarizing agents in magnetic resonance imaging (MRI) and diagnosis, and as agents for magnetic hyperthermic treatments. Academically, molecule-based magnets are also studied intensively with regard to their important fundamental chemistry and physics, since they have the potential to be exploited in nanoscale electronics devices, as beautifully demonstrated recently by the construction of single-molecule spintronic devices (spin valves and transistors). Molecule-based materials offer the great advantage of being designable and manipulable by synthetic chemistry. That is, they can be constructed atom by atom, molecule by molecule with the unparalled advantages of being soluble, monodisperse in size, shape and physical properties, and tuneable at the atomic scale. Indeed, this "bottom-up" research vision is not restricted to academia - IBM recently reported information storage in surface-isolated (2x6) arrays of Fe atoms at liquid He temperatures and are actively investigating spintronics and data storage with a view to the ultimate miniaturisation of such technologies. However, before any molecule or molecule-based material can have commercial application or value, the fundamental and intrinsic relationship between structure and magnetic behaviour must be understood. This requires the chemist to design and construct familes of related complexes, characterise them structurally and magnetically, and through extensive collaboration with a network of world-class condensed matter physicists and theoreticians, understand their underlying physical properties. The current proposal directly addresses these fundamental questions through the controlled aggregation and organisation of molecular magnets into designed 0-3D architectures in the solid state. Specifically it applies the fundamental principles underpinning supramolecular chemistry to assemble single-molecule magnets into novel topologies by taking advantage of simple coordination-driven self-assembly processes. We will employ molecular magnets as building blocks for the formation of supramolecular assemblies and coordination polymers in which the spin dynamics of the molecular building blocks are modulated through the attachment of, and interaction with, other paramagnetic moieties. In order to achieve this we will: design and build a range of metalloligands, ranging from simple isotropic molecules to more complex and exotic anisotropic molecules and attach them to pre-made SMMs; construct hybrid magnetic materials from SMMs and cyanometalate building blocks; design and synthesise dual-functioning ligands which are capable of directing the formation of SMMs and simultaneously linking them into higher order (O-3D) materials; and characterise all materials, structurally and magnetically, through a battery of techniques.