The discovery of new materials for electronic, magnetic and energy techmology applications motivates much of modern chemistry, physics and materials science. High pressure methods are important for materials synthesis and for inducing new electronic states. This project will explore exciting new materials and also new ideas for materials discovery that go beyond standard high pressure synthesis approaches. In our high pressure materials syntheses, a chemical reaction is carried out at pressures up to 150,000 atmospheres pressure and temperatures up to 1500C. Afterwards the sample is cooled and then decompressed to ambient conditions. In successful cases, a novel material with a new chemical composition or structure is found to have been 'recovered' from the high pressure and temperature reaction conditions. This is a successful discovery strategy for dense, oxide-based, inorganic materials and will be applied to several specific cases. Magnetite is the original magnetic material and remains of fundamental interest and of practical importance in new technologies such as spintronic devices. We have recently solved a long-running problem (first identified in 1939) concerning the low temperature electronic structure of magnetite and we discovered unexpected 'orbital molecule' states where electrons are spread over three adjacent iron atoms. In this project we will use high pressure synthesis to recover new chemically-substituted analogues that preserve the essential electronic features of magnetite, in order to discover new 'orbital molecule' states or arrangements. Ruthenium also forms important magnetic oxides such strontium ruthenate which is used in spintronic and silicon thin-film electronics devices. We have recently discovered a new familty of ruthenium oxides, and high pressure will be used to explore their chemical composition range and electronic and magnetic properties. Oxynitride (oxide-nitride) materials are important for energy technologies as photocatalyts that split water to generate hydrogen, and as phosphors for WLED white-light emitting semiconductor devices. WLED devices are an excellent example of how device innovation (discovery of GaN-based blue LEDs) and materials chemistry (discovery of nitride phosphors) have led to real energy savings on a global scale. We will use a direct high pressure synthesis route to generate new oxynitrides and explore their propeties through collaboration. The successful preparation of a material is usually the chemical end point for high pressure synthesis, but we will also explore new approaches where a synthesised high pressure material is the starting point for chemical investigations. This can be described as a 'hard-soft' method to generate novel materials by relieving the instability of a dense precursor made under 'hard' high pressure and temperature conditions through 'soft' post-synthesis modification. Recent proof-of-concept results have shown that 'hard-soft' chemistry can generate new transition metal oxides beyond high pressure synthesis. We will also perform high pressure measurements of electronic and magnetic properties of recovered materials to discover electronic properties beyond those at ambient pressure, including very low temperature regimes where quantum mechanical variations are important.

Electronic and magnetic materials are important to many current and likely future technologies e.g. superconductors for low energy power transmission and new magnets for sensors, information storage and future quantum computers. Exploration of properties at extremes of low (or high) temperature, high magnetic field and high pressure is important to discover new phenomena and to help understand current outstanding electronic and magnetic materials. To do this we propose to construct the Measurements Platform for Materials at Multiple Extremes (MPMME) as a unique facility for measurements of electronic and magnetic properties under multiple extremes of temperature (down to 300 mK or up to 1000 K) and magnetic field (up to 14 T), and also pressure (up to 100 GPa). It will be essential for supporting current and future research on materials varying from heavy fermion superconductors to transition metal oxides to molecular magnets. The proposed MPMME has two parts; 1. A commercial instrument for physical property measurements (heat capacity, magnetic susceptibility, electronic and thermal transport) at extremes of temperature and field. 2. High pressure capabilities for transport and magnetic measurements will be added through auxiliary equipment designed and built in CSEC (the University of Edinburgh's Centre for Science at Extreme Conditions) which has a strong record of instrumentation design for high-pressure research. New pressure cells will provide state-of-the-art pressure capabilities for the MPMME such as non-metallic cells for high frequency AC measurements, and a Megabar diamond-anvil cell for very high pressures. The discovery of new electronic and magnetic materials is a challenge requiring the combined skills of chemists, physicists, and engineers and the applicants have strong backgrounds in these different disciplines that will be combined to achieve our ambitious goal of discovering new materials with notable properties. UK and international collaborations will be strengthened by measurements made with the MPMME facility. It will also augment the training that we can provide to our students and PDRA's, and underpin equipment commercialisation and our outreach activities.

Multi-specimen combinations of large, melt processed YBCO single grains of 25 mm diameter have been shown to trap stable magnetic fields as high as 17 T at 29 K in research-grade samples, which are simply not achievable in conventional iron-based permanent magnets (limited practically to less than ~ 1.5 T). Unfortunately, achieving and maintaining a bulk, superconducting device operating temperature of less than 65 K is difficult from a practical point of view and not particularly cost-effective. It is necessary, therefore, to develop materials with improved flux pinning (and hence field trapping) properties that can be fabricated economically for deployment in industrial applications based either on cryo-cooler technology, or on systems that use liquid nitrogen as a cryogen (boiling point, 77 K). Large single grains can be incorporated directly into existing sustainable engineering applications such as flywheels, magnetic bearings, permanent magnets for MRI/NMR, non-contact magnetic stirrers for high purity biological solutions and magnetic separators provided they can trap at least 2.0 T at 77 K. The closer the operating temperature to the transition temperature of the large single grain (typically ~ 90 K), however, the greater the requirement for effective artificial flux pinning centres in the large grain microstructure that prevent the motion of magnetic flux within the sample. The optimum size of such pinning centres is typically around a few nano-metres at 77 K. The most common method of introducing pinning centres into large YBCO grains involves engineering the size of Y2BaCuO5 (Y-211) phase inclusions in the bulk microstructure, which are produced as part of the Y-123 peritectic decomposition process during melt processing. The technique is limited fundamentally, however, by the tendency of Y-211 particles to ripen at elevated temperature, which conflicts directly with attempts to refine their size to the nano-scale. This results inevitably in a significant reduction in control of the melt process, and hence to limitations in sample performance. The PI has been involved in two important recent developments of the processing of large grain (RE)BCO superconductors. These are the development of a suitable non-211 phase that forms effective nano-scale artificial flux pinning centres, and in the development of an entirely new type of seed crystal that enables every member of the (RE)BCO class of materials to be grown in the form of large single grains by a practical techniques for the first time. The primary objective of this highly challenging project, therefore, is to fabricate mechanically stable, large, state of the art samples of single grain YBCO and other (RE)BCO melt processed superconductors than has been possible previously that contain novel (i.e. non Y-211-based), effective nano-scale artificial flux pinning centres by a practical processing technique. This will enable for the first time the cost-effective application of bulk superconductors in sustainable engineering devices that operate at, or around, 77 K. Additional objectives of this challenging proposal are to fabricate complex-shaped, new nano-phase composites for be-spoke applications for the first time using a novel multi-seeding technique, also underdevelopment at Cambridge by the PI, and to establish for the first time an effective recycling process for multi-grain samples. The project will involve extensive collaboration with four Cambridge science departments (Engineering, Materials Science, Physics and Chemistry) and with three international institutions (ATI Vienna, ICMAB Barcelona and the Boeing Company Seattle).

Computers and electronic gadgets, such as the iphone, have transformed modern life. The silicon transistor is at the core of this revolution, having been continuously made faster and smaller over the last forty years. In a chip, millions of them are squeezed into an area the size of a pinhead, switching a billion times in one second. Transistor size has now reached nanometre dimensions; one nanometre is only ten time larger than an atom. Moore's law, which dictates that transistor size halves every two years and is the driving force behind the success of the electronics industry, has come to a halt. The happy and easy days of transistor scaling are now gone. Quantum mechanical laws conspire against transistor function making it leak when switched off and generating poor electrical control. Also, our inability to control the precise atomic structure of interfaces and chemical composition during fabrication makes transistors less predictable. Hence semiconductor companies are searching for alternative, non-planar (multigate) transistor architectures and novel devices such as nanowires, nanotubes, graphene and molecular transistors, which will ultimately break through the nano-size barrier resulting in a completely new era of miniaturization. There is a significant gap between our ability to fabricate transistors and to predict their behaviour.The simulation and prediction of the silicon transistor has become an vital mission. Current planar transistor architecture presents serious problems in scalability regarding leakage and controllability. Transistors of nanometre dimensions are more vulnerable to the atomic nature of matter than their previous cousins of micrometre dimensions. Furthermore, at nanoscales heat transfer is a source of heat death for novel transistor applications due to the decrease of thermal conductivity. Within this context I propose to develop a Quantum Device simulator, with atomic resolution that will enable the accurate prediction of present and future transistor performance. The simulator will deploy a quantum wave description of electron propagation, treating the interaction of electrons with crystal lattice vibrations (heat) at a fully quantum mechanical level. It will have the capability of describing the electron interactions with the roughness of the semiconductor/dielectric interface and with each other under the effect of a high electric field. Devices will be properly tested and optimised regarding materials, chemical composition and geometry without the high costs implicit in fabrication. A wide range of transistors will be explored from planar, non-planar and novel. This is timely as existing computer design tools lack predictive capabilities at the nanoscale and the industrial build-and-test approach has become prohibitively costly. Efficient quantum-models/algorithms/methodologies and tools will be developed.These are dynamic times as device dimensions move closer to the realm of atoms, which are inherently uncontrollable. In this regime two streams collide: the classical and quantum worlds making the need for new regularities and patterns vital as we strive to conquer nature at this scale. This offers exiting opportunities to merge an engineering top-to-bottom approach with a physics bottom-up approach. As 21st century environmental concerns rise, the need for greener technology is increasing. My proposal addresses the lowering of power consumption, raw material reductions delivering more functionality and the provision of a cheaper way to assess new design technologies. Collectively, these will help companies to provide a greener alternative to consumers.

Computers and electronic gadgets, such as the iphone, have transformed modern life. The silicon transistor is at the core of this revolution, having been continuously made faster and smaller over the last forty years. In a chip, millions of them are squeezed into an area the size of a pinhead, switching a billion times in one second. Transistor size has now reached nanometre dimensions; one nanometre is only ten time larger than an atom. Moore's law, which dictates that transistor size halves every two years and is the driving force behind the success of the electronics industry, has come to a halt. The happy and easy days of transistor scaling are now gone. Quantum mechanical laws conspire against transistor function making it leak when switched off and generating poor electrical control. Also, our inability to control the precise atomic structure of interfaces and chemical composition during fabrication makes transistors less predictable. Hence semiconductor companies are searching for alternative, non-planar (multigate) transistor architectures and novel devices such as nanowires, nanotubes, graphene and molecular transistors, which will ultimately break through the nano-size barrier resulting in a completely new era of miniaturization. There is a significant gap between our ability to fabricate transistors and to predict their behaviour.The simulation and prediction of the silicon transistor has become an vital mission. Current planar transistor architecture presents serious problems in scalability regarding leakage and controllability. Transistors of nanometre dimensions are more vulnerable to the atomic nature of matter than their previous cousins of micrometre dimensions. Furthermore, at nanoscales heat transfer is a source of heat death for novel transistor applications due to the decrease of thermal conductivity. Within this context I propose to develop a Quantum Device simulator, with atomic resolution that will enable the accurate prediction of present and future transistor performance. The simulator will deploy a quantum wave description of electron propagation, treating the interaction of electrons with crystal lattice vibrations (heat) at a fully quantum mechanical level. It will have the capability of describing the electron interactions with the roughness of the semiconductor/dielectric interface and with each other under the effect of a high electric field. Devices will be properly tested and optimised regarding materials, chemical composition and geometry without the high costs implicit in fabrication. A wide range of transistors will be explored from planar, non-planar and novel. This is timely as existing computer design tools lack predictive capabilities at the nanoscale and the industrial build-and-test approach has become prohibitively costly. Efficient quantum-models/algorithms/methodologies and tools will be developed.These are dynamic times as device dimensions move closer to the realm of atoms, which are inherently uncontrollable. In this regime two streams collide: the classical and quantum worlds making the need for new regularities and patterns vital as we strive to conquer nature at this scale. This offers exiting opportunities to merge an engineering top-to-bottom approach with a physics bottom-up approach. As 21st century environmental concerns rise, the need for greener technology is increasing. My proposal addresses the lowering of power consumption, raw material reductions delivering more functionality and the provision of a cheaper way to assess new design technologies. Collectively, these will help companies to provide a greener alternative to consumers.