Summary
Funded PhD Positions
Royal Society PhD project
Title: Atomic Scale Design of Dynamic Quantum Materials
Please reach out to me for details on application: mconroy@imperial.ac.uk
Description:
Dynamic structures with non-trivial topology — such as skyrmions, merons, and domain walls — are rich sources for emergent functional phenomena, enabling local control of magnetic, electronic and ionic transport properties, phonons and more. Higher-order topological charge and spin textures in quantum materials provide a route to develop a plethora of dynamic nanoelectronics, spintronics and quantum devices. Building on the recent progress in our groups, this PhD project will develop thin film growth methods of oxide based quantum materials at the new state-of-the-art Imperial Royce facilities.
Due to the complex local atomic scale structure of such dynamic topologies and related crystallographic defects, it is essential for the physical characterisation to be time-resolved and at this scale spatially. The student will apply the latest tools in in-situ electron microscopy, diffraction and spectroscopic characterisation. Using sub-ångström electron beam probes the student will be able to draw and move exotic topologies in the materials they have grown, while analysing changes in their functional properties such as electric and magnetic field. In collaboration with the Imperial-X centre the student will incorporate machine learning approaches to probe the atomic-scale dynamics of the materials
The position is suitable for those with a background in chemistry, physics, nano-electronics, or materials science with an interest in quantum materials, atomic scale microscopy and scientific computing. The student will also utilise the new Cryogenic Transmission Electron Microscopy and the UK National Research Facility for Advanced Electron Microscopy SuperSTEM.
Institution: Imperial College London
Supervisor(s): Dr Shelly Conroy(ICL), Prof Neil Alford (ICL), Dr Peter Petrov (ICL) Sponsor(s): EPSRC & Royal Society
Placement: The student will do a placement at the UK National Research Facility for Advanced Electron Microscopy SuperSTEM. The student will spend a research internship at the Molecular Foundry, Lawrence Berkeley National Laboratory working in Dr Colin Ophus’ and Dr Sinéad Griffin’s groups.
Essential candidate background/skills: Candidates must have a First Class or Upper Second-Class honours degree in an appropriate field such as Physics, Chemistry, Materials Science, Engineering or a related subject.
Nationality restrictions: UK or Irish citizens, or EU student with settled or pre-settled status, who has resided in the UK for the past 3 years
Example of research: Charged Domain Wall and Polar Vortex Topologies in a Room-Temperature Magnetoelectric Multiferroic Thin Film
PhDs with the CDT in Advanced Characterisation of Materials
Please reach out for application information: mconroy@imperial.ac.uk
Project 1: Exploring Novel Polar Topologies for Low Power Nano-electronics
Description: Devices based on nanoscale ferroelectric polarisation structures with unusual polar topologies overturn the classical idea that our electronic circuits need to consist of fixed hardware components. Ferroelectric domain walls, polar vortices and polar skyrmions can be easily created, destroyed and moved about simply by an applied stimulus, without harming the crystal structure, thus making them ideal for reconfigurable electronics. At the same time, their diverse physical properties, which are distinct from those of the host material, combined with their dynamic nature and low power requirements, bring new functionality to a range of devices, including transistors and capacitors for conventional logic and storage, and memristive elements for neuromorphic computing. However, to harness their true potential there is a great deal of fundamental physics yet to uncover. As domain walls are usually only a few atoms thick and highly dynamic, it is essential to characterise them at the relevant spatial and temporal scale.
Institution: University College London & Imperial College London, with a research placement at SuperSTEM
Supervisor(s): Dr Pavlo Zubko (UCL) & Dr Shelly Conroy (ICL)
Sponsor(s): EPSRC
Placement: The student will spend one month in year 2 and 3 at SuperSTEM the EPSRC National Research Facility for Advanced Electron Microscopy, where they will be able to access the state-of-the-art atomic-scale electron spectroscopy characterisation facilities. The specialised high-energy-resolution facility will allow the student to study the band-structure and phonon modes of the domain walls. https://www.superstem.org/ The student will also spend one month at the US National Centre of Electron Microscopy (Berkeley National Laboratory) within the AI/ML 4D-STEM data processing group of Dr Colin Ophus. Conditional on visa requirements. https://foundry.lbl.gov/
Essential candidate background/skills: Candidates must have a First Class or Upper Second-Class honours degree in an appropriate field such as Physics, Chemistry, Materials Science, Engineering or a related subject.
Nationality restrictions: UK or Irish citizens, or EU student with settled or pre-settled status, who has resided in the UK for the past 3 years
Suitable for part-time/flexible study: Yes
Example of research: Metal–ferroelectric supercrystals with periodically curved metallic layers
Project 2: Battery Materials investigated by Atomic-scale Cryogenic Microscopy Characterisation
Description: Improving the lifetime and performance of energy storage devices is key to a green-energy society. The interface of the electrolyte and electrode plays the most crucial role in batteries and capacitors. However due to the liquid phase of the electrolyte and the volatile nature of Li, characterising this region is challenging. Cryogenic sample preparation and microscopy analysis exploited for biological research has more recently been used for battery characterisation. The cryogenic vacuum conditions allows one to have an undistorted view of the resulting electrochemical reactions at these very complex interfaces. In this project we will investigate new compositions of nanomaterials and deposition methods for the next generation energy storage. There is a vast field of unexplored fundamental questions to be addressed for these energy materials that is only possible now with the development for cryogenic microscopy instrumentation and direct electron detectors for damage free imaging and spectroscopy.
This project will aim to investigate:
• The relationship between the electrode-electrolyte interface and the performance of lithium-ion batteries.
• The complex structure of the solid-liquid interface at the atomic-scale, with an emphasis on probing the light and volatile element such as Li and H.
• Changes in chemical bonding within the interfaces
The student will be integrated into the new EPSRC UK National Centre for Cryogenic Microscopy facility at Imperial College London. The unique facility allows for sample transfer, under controlled atmosphere and at cryogenic temperature, between a high-end aberration-corrected transmission electron microscope and an atom probe, allowing for structural and compositional imaging of materials with an unprecedented precision. The student will also have access and support for data processing and simulations from the Imperial-X, the new centre for artificial intelligence, data science and digital technologies.
Institution: Imperial College London and Cameca R&D USA site.
Supervisor(s): Dr Shelly Conroy(ICL), Prof Finn Giuliani (ICL), Prof Baptiste Gault (ICL & Max Planck Dusseldorf) Sponsor(s): EPSRC & Cameca
Placement: The student will spend 3 months at Max-Planck-Institute für Eisenforchung GmbH, in Düsseldorf, Germany within the APT research group of Prof Gault who holds a joint appointment with ICL. The student will be able to access the well-established cryogenic FIB based APT sample preparation characterisation facility and expertise, then bring this knowledge and experience back to ICL to combine TEM and APT cryo investigations.
The student will spend time at the USA R&D site for Cameca and work with the atom probe development engineers.
The student will work closely with the in-situ liquid electrochemistry TEM group of Prof Caterina Ducati at University of Cambridge and the Faraday Institution. The student and PI Dr Conroy will have regular trips to Prof Ducati’s lab and arrange combine liquid cell TEM with cryogenic TEM and APT.
Essential candidate background/skills: Candidates must have a First Class or Upper Second-Class honours degree in an appropriate field such as Physics, Chemistry, Materials Science, Engineering or a related subject.
Nationality restrictions: UK or Irish citizens, or EU student with settled or pre-settled status, who has resided in the UK for the past 3 years
Suitable for part-time/flexible study: Yes
Example of research: Understanding the Degradation of a Model Si Anode in a Li-Ion Battery at the Atomic Scale
Project 3: Novel Scanning Acquisition Design and All-digital Detection Strategies in STEM
Description: The transmission electron microscope has been called “A Synchrotron in a Microscope” (L.M. Brown, 1997). Scanning TEM, or STEM, now delivers this analytical power point-by-point for every pixel in a scanned field of view, enabling atomic resolution imaging and chemical analysis.
In recent years, new programmable scan-generators allow the operator to design advanced scanning patterns beyond classical raster scanning. These can be used to improve the image resolution, compensate for flyback hysteresis, or for novel geometries of scan-patterning such as interlacing. However, so far only a small fraction of their functionality has been exploited.
Similarly, recent developments in electron detection has enabled all-digital read out and single electron sensitivity to be reached. These techniques allow for the precise number and timing of every electron scattering event to be recorded.
Both of these new technologies each promise to deliver more dose-efficient imaging, and there is now a huge opportunity to combine these two state-of-the art approaches. This project will explore the mutually beneficial fusion of these two approaches into a single framework. The research will involve:
- Developing an each-electron approach to image simulation design,
- Developing a programmable (Python) framework for novel acquisition design,
- Being able to independently operate atomic-resolution TEM instruments,
- Integrating single-electron sensitive detectors into a time-coded pipeline,
- Synchronisation between illumination and detection events,
- Prediction, measurement and tracking of electron dose exposure, and
- Ultra-high precision and SNR imaging of beam-sensitive materials.
Institution: Trinity College Dublin & Imperial College London
Supervisor(s): Prof Lewys Jones (TCD) & Dr Shelly Conroy (ICL)
Sponsor(s): SFI
Placement: A placement is planned to take place in year 3 with an industrial collaborator Bryan Reed of IDES based in California, USA.
Essential candidate background/skills: Candidates must have a First Class or Upper Second-Class honours degree in an appropriate field such as Physics, Chemistry, Materials Science, Engineering or a related subject.
Nationality restrictions: EU and UK citizens
Example of research: Using Your Beam Efficiently: Reducing Electron Dose in the STEM via Flyback Compensation
