Our interest is in understanding the structure of non-periodic systems (e.g. glasses, liquids, nanoparticles) where powerful x-ray scattering methods encounter significant experimental and fundamental limitations. Analysis of pair distribution function (PDF) and of x-ray absorption data has been shown to provide information sufficient to address some of the issues [1-3]. However, there are still significant challenges in the interpretation of both x-ray absorption spectroscopy (XAS) and in x-ray scattering data that prevent recovering exact structural models form experiments. We have recently demonstrated [4] that an accurate description of the disorder can achieved by utilising information about interatomic interactions. This results in significant improvements in PDF/XAS analysis and can even be used to extract information about interatomic potentials. However, this approach has so far only been tested in molecular dynamics simulations and in model colloidal systems.
With this project we aim to apply our method to the condensed matter systems by adopting it for PDF and XAS analysis, thus also providing an approach to the treatment of disorder unified across complementary techniques. Once tested, it will be utilised to address significant current challenges in solving the structure of ultra-small nanoparticles. These novel systems possess a number of unique properties, which include recently reported isomerisation-like behaviour [1,2] and access to the previously unavailable thermodynamic phase space [5]. Furthermore, the proposed approach will pave the way towards analysis of systems under supercritical conditions - a domain of materials science where structural methods are likely to make a significant impact in the coming decades.
This position is fully-funded for 3 years by Diamond Light Source (DLS) Plc and Queen Mary University of London and covers fees for UK/Home nationals. The successful applicant will be expected to spend at least 50% of their time at the DLS during the Studentship. This is an excellent opportunity to work at the world leading institution and to engage with the world-leading synchrotron radiation facility. Please contact Dr Andrei Sapelkin ([Email Address Removed]).
Applications can be made via the admissions portal, applicants are advised to highlight project name on the application.
https://www.qmul.ac.uk/postgraduate/research/subjects/physics-and-astronomy.html
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