Vacancies

Vacancies:

Research Fellow in Coherent Diffraction Imaging

Applications are invited for a Research Fellow in the broad area of coherent diffraction imaging (CDI) of quantum materials at the nanoscale. This role is part of the recently funded UKRI project on 'Time Resolved Imaging of Quantum Multifunctional Materials'. This role is focussed on utilising CDI techniques to image time-varying phenomena in a range of multifunctional materials using our unique laboratory based x-ray imaging equipment along side synchrotron and XFEL facilities. We are particularly interested in the quantum properties of correlated materials at the nanoscale for potential applications such as ultra-fast optical switches and low power magnetoelectronic devices.

The successful candidate will engage with the wider x-ray imaging and materials physics community as well as industry and the general public in outreach activities. Full details of the role are found in the job description and person specification. The successful applicant must have a PhD or equivalent qualifications in Physics, Materials Science, Optoelectronics, Engineering or a related field.

Apply now here.

Imaging Multifunctional Nanomaterials in Three-Dimensions with Coherent X-rays

Multifunctional materials that simultaneously exhibit more than one ferroic property including ferromagnetism, ferroelectricity, ferroelasticity or ferrotoroidicity are of great interest because the different properties may work together in different ways and lead to exciting new potential applications, if we could understand this better. For example, the coupling between magnetic and ferroelectric ordering can be utilised to develop low power magnetoelectronic devices (such as non- volatile magnetic computer memory) where the spin polarised transport of electrons can be used to flip magnetic memory bits. As a result there is a vibrant effort to understand the underlying mechanisms at work in bulk and thin film materials. Often the role of crystal defects and other topological structures remains unclear as (to date) no reliable means exists to image in three-dimensions and observe such effects in real-time. In addition, common Li-ion battery cathode materials such as Li_xCoO₂ (LCO) allow high capacities and reliable cyclability, but suffer from structural degradation over repeated charging cycles.

The aim of this project is to image time-varying correlated phenomena in a range of multifunctional materials. The results will (1) facilitate in identifying new and potentially novel applications for the materials of interest, (2) provide insight into scale-invariant properties of correlated material systems and (3) provide improved performance of battery materials.

To better understand these materials we will use a technique called Bragg coherent X-ray diffractive imaging (BCXDI) without lenses to reveal how novel phases emerge and influence the material properties. The application of BCXDI to the study of multifunctional materials will enable a wide range of next generation technologies that otherwise are inaccessible due to an incomplete understanding of their properties. The successful candidate will spend approximately 50% of their time on the project working at the Diamond Light Source, located at the Harwell Science and Innovation Campus in Oxfordshire.

Applications are invited from bright and highly motivated students with a background in physics, materials science, inorganic chemistry or a related field. The successful candidates will have obtained either a First or Upper Second class honours degree.

Imaging Quantum Materials with an XFEL

Quantum materials can often exhibit novel and multifunctional properties due to strong coupling between lattice, charge, spin and orbital degrees of freedom. When perturbed into an excited state, non-equilibrium phases often emerge on the femtosecond timescale. They include light-induced superconductivity, terahertz-induced ferroelectricity and ultra-fast solid-phase structural transformations. Understanding non-equilibrium phases in quantum materials is of great interest for the development of next generation technologies and to better understand the underlying mechanisms. To further understand these hidden phases, tools to probe quantum materials with femto-second time-resolution are required.

X-ray Free Electron Laser (XFEL) facilities provide ultra-short pulses of coherent x-rays that make it possible to measure ultra-fast dynamics in quantum materials simultaneously with nanoscale spatial resolution and femto-second time resolution. While preliminary work has begun on the use of XFELs to study quantum behaviour in materials, there are a wide range of strongly correlated materials that exhibit novel behaviour that is not well understood.

This project will investigate strongly correlated phenomena in nanoscale quantum materials using time-resolved Bragg coherent diffraction imaging (CDI) at various XFEL facilities. Initial emphasis will reside on the study of structural phase changes in strongly correlated quantum materials such as vanadium dioxide but will continue to expand to other material systems throughout the duration of the project. The overarching goal is to directly observe atomic motions during the event of a quantum phase transition. The ability to quantitatively observe atomic motions within the transition state region where atoms exchange nuclear configurations will greatly facilitate our understanding of the physical processes.

This project is fully funded for 3.5 years, supervised by Dr Marcus Newton and will benefit from access to the European XFEL, Swiss XFEL, SACLA XFEL and PAL XFEL. A background in physics, materials science or inorganic chemistry is desirable but not essential.