Graduate Research Projects in the SMF Group (PhD and MPhil Degrees)
Understanding the dynamical properties of materials, from individual atoms and molecules on surfaces, to the effect of defects and bulk structure remain substantial physical challenges. In the SMF group, we aim to investigate the physics of such processes at the most fundamental level practical.
Across the group, we apply an exceptionally wide range of experimental techniques, from nano-scale imaging to macroscopic materials tests, and we have a strong emphasis on development of innovative experimental techniques. Our projects are primarily experimental, but the group also pursues a considerable computational modelling effort - ideal for those people wishing to focus on modelling or theory, while maintaining a grounding in experiment.
Application and Funding
Information about the application procedure is available on the departmental website. All projects are available to students applying for Departmental Quota Award studentships or other personal awards. In addition, there are a number of other studentships available for work in specific areas, and many projects have dedicated funding streams.
PhD Projects for 2017 Entry
Underpinning the recycling of CO2 (Dr J Ellis, Dr AP Jardine)
Greenhouse gas reduction, and especially CO2 reduction, is one of the greatest challenges to our society. Copper mediated hydrogenation of CO2 to form methanol (“MeOH”) is one of the most promising reactions with respect to recycling of greenhouse gas emissions, as not only does it reduce CO2, it also offers alternative fuel production. The aim of this project is to use nano-confinement methods to study the dynamics of CO2 and methanol on copper surfaces. Understanding the mobility of reactants and products is a critical step in CO2 conversion and He spin-echo spectrometry (HeSE) is an ideal tool to study the process. The method enables detailed dynamical analysis, comparison with theoretical efforts, and has a special sensitivity to hydrogen atoms, such as in methanol. This is an experimental project, but there is opportunity for substantial computational modelling and interaction with a variety of international collaborators.
Hydrogen mobility on surfaces (Dr J Ellis)
Understanding hydrogen mobility is vitally important to the modern world, from fuel cells, to energy storage, to the embrittlement of metals. However, the fundamental processes controlling its motion between atoms is still not well understood – even the relationship between classical hopping and quantum tunnelling between different surface sites cannot easily be predicted. The aim of this project will be to experimentally study the transition from classical to quantum H motion on metal surfaces, using helium spin-echo spectroscopy (HeSE). The method represents a unique experimental approach pioneered in Cambridge, which provides unprecedented data quality and precision. There will be opportunities to link the project with theory, to model the experimental data, depending on individual interests. Some collaboration with national and international collaborators (both experimentalists and theorists) is very likely.
Dynamic processes in organic film assembly (Dr J Ellis) (†)
Organic films are of wide-ranging importance; for example in organic electronics as a technology for low cost devices, or in large scale solar cells. The performance of such devices is controlled by the quality of preparation of molecular thin films and heterostructures. Since top-down structuring methods like lithography cannot be applied to van der Waals bound materials, surface diffusion becomes a structure determining factor that requires microscopic understanding. The aim of this project will be to study the dynamics of species relevant to the organic electronics industry, including pentacene and fluorinated variants thereof, which enable the level of conjugation to be tuned. The project will include organic monolayer optimisation, dynamics data collection, and analysis. There will be opportunity to combine experiments with extensive molecular dynamics simulations, to further interpret the experiments, depending on individual interests. The project will involve collaboration with researchers in Germany.
Next Generation Microscopy with Atoms (Dr AP Jardine) (†)
We have recently developed a revolutionary new form of microscopy using neutral atoms (see case study). The method is ultra-sensitive, and will enable many previously inaccessible surfaces to be studied, ranging from light sensitive molecules, to polymers making up MEMS structures. The aim of this project will be to push the bounds of the technique, and explore the use of matter wave-effects in contrast formation (i.e. diffraction and interference contrast). The project will tie in closely with the team supporting the ongoing microscope development programme, so will suit a keen experimental physicist who is prepared to get their hands dirty in the lab. It will benefit from ongoing collaborations with European and Australian physicists.
Morphology and Growth of Ice (Dr AP Jardine)
Ice is a vitally important material, yet is still not well understood. A range of unusual and complex morphologies are formed during low-pressure growth, ranging from regular arrangements to complex ‘worm-like’ structures. However, it is almost impossible to study these structures at high resolution – electron microscopy causes melting, and scanning probe techniques cannot cope with the high aspect ratio structures that are formed. The aim of this project is therefore to study the growth / structures formed by ice using helium microprobes – one of the few suitable tools. The project will involve both helium scattering and helium microscopy, using existing equipment developed in the group. The project is primarily experimental, but could be extended to include simulation/modelling. It will involve working closely with international collaborators.
Nanoscale control of single crystal diamond mechanics (Dr AP Jardine) (†)
Diamond is an immensely important material both from a fundamental perspective, and in applications as diverse as quantum-computer development and highly optimised mechanical tooling. Many diamond properties are closely related to the defect structure within the material (e.g. carbon vacancies, impurities). Mechanically, the strength and toughness of diamond are both closely linked to the atomic scale defect-structure, but are vital to optimising its use in tooling.
Techniques are available to modify diamond on the nanoscale, and the overall aim of this project is to improve our understanding of the relationship between nanostructure and macroscopic mechanical properties. It will involve characterisation of nanoscale properties, performing experiments to study macroscopic mechanical characteristics and running computer simulations to examine the structure of defects, and to bridge the gap between nano- and macro- regimes. The project will form a collaboration with a major industrial partner, and the candidate will benefit from the opportunity to work directly with them for a period of time.
Effect of structure on dynamics of geological materials (Dr C Braithwaite)
The dynamic mechanical response of geological materials is of great importance, both industrially and scientifically, with applications ranging from seismology and planetary impact, to oil exploration and mining. The materials themselves are often complex and polycrystalline with a variety of constituent minerals and wide range of inherent length scales. While significant research has been conducted in the field, currently there is a lack of data examining the effect that the microstructure plays in determining strength parameters. This project aims to use a variety of existing high strain rate experimental equipment to examine the response of geological materials. Novel methodologies and diagnostics will need to be developed to monitor grain level behaviour and relate this to macroscale properties. Interaction with computational modelling will also be sought, to enhance the understanding of the experimental results obtained. The research group has substantial experience in this area and maintains a variety of relevant industrial contacts.
Granular materials under high rates of compaction (Dr CH Braithwaite)
The processes by which brittle granular materials compact largely depend on their microstructure and the properties and interactions of the grains themselves. Predicting the dynamic response of these systems requires knowledge of how grain-scale phenomena manifest as macroscopic response. Such insight is crucial for a wide range of high rate applications including planetary formation and impact cratering, the response to blast and
penetration, and predicting and improving soil response to earthquakes and landslips through seismic coupling. This project will follow on from a highly successful project studying the shock compaction of cohesionless sands at different moisture levels; it will extend the research programme to silts (smaller grain sizes), cohesive materials such as clays, and will begin to study how granular compaction can be controlled using suitable ‘modifiers’.
Ultra-fast temperature sensors for shock (Dr DM Williamson)
Accurate temperature measurement during high speed events remains a consistent problem in shock-physics. Existing transducers are rate limited by their thermal mass, whereas standard optical techniques can only be applied under limited conditions (usually very high temperatures). In this project, we will focus on developing new techniques for ultra-fast temperature measurement. These will include modelling, fabrication and testing of nanometre-scale thermistor based instrumentation and fast response infra-red pyrometry. The techniques will be applied to study shock temperatures in polymeric and liquid systems, which are of increasing industrial importance.
Adhesion and damage in composites (Dr DM Williamson)
Composite materials are of great importance in the everyday world. Their fundamentally inhomogeneous nature means composites can exhibit complex forms of behaviour, relating to characteristics of the binder, filler and the nature of the interaction between them. This project will focus on predicting the behaviour of composites using physically based models, supplemented by experimental data. Low temperature thermo-physical measurements enable key model parameters to be populated. Predictions may then be validated using other, mechanically based, measurements. It will suit a keen experimentalist, and will likely involve extensive collaboration with other researchers.
(†) – Project to be funded through EPSRC award scheme, or other awards.
(*) – Project to be funded directly, through dedicated project based funding.