People


 Academic Staff

Michael Moody

Prof Michael Moody

Head of Atom Probe Research Group

Associate Professor of Materials Science

Phone: +44 1865 273693

michael.moody@materials.ox.ac.uk

Michael is the Head of the Atom Probe Research Group in the Department of Materials at the University of Oxford. The group currently leads and supports research into a wide range of materials topics including: superalloys for aerospace applications, structural materials for fusion and fission power, Si and GaN semiconductors and catalysis. To this end, we collaborate with scientists and engineers from around the world on a wide range projects. A key focus of my own recent research has been the design of new analytical techniques to improve the accuracy of the reconstruction of atom probe data and to increase the information obtainable from subsequent analysis of the results. However, the group has active interests in all aspects of atom probe research and places a significant emphasis on developing advanced techniques and applications.

Please contact Michael if you are interested in collaborating with us and/or would like to know more about our atom probe facilities.

Dr Michael Moody - Materials Oxford Homepage (with summary of research interests and full list of publications)


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Prof. George Smith FRS

Professor George Smith FRS

Emeritus Professor in Materials

george.smith@materials.ox.ac.uk




 George was leader of the atom probe group for over 40 years, where his work included the development of the first three-dimensional atom probe instrument in the world, designed at Oxford in the late 1980s. George is the recipient of many awards for his scientific contributions, including the 2005 Acta Gold Medal, 2006 Institute of Materials Plartinum Medal and more recently the 2016 TMS Hume-Rothery award. George retired in 2011 but as Emeritus Professor he still plays an active role in the group working on interests such as atom probe analysis of phase transformations, studies of the role of alloy elements and trace additions on the microstructure, heat treatment and properties of steels and non-ferrous alloys. Atomic scale studies of heterogeneous catalysts.

Professor George Smith - Materials Oxford Homepage (with summary of research interests and full list of publications)

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Research Fellows

 

Dr Maria Auger

Dr Maria A Auger

Postdoctoral Research Assistant

Characterisation of the microstructure of ODS Fe-Cr Alloys

Phone: +44 (0) 1865 273634

maria.auger@materials.ox.ac.uk

Maria’s research background is mainly devoted to the preparation and processing of materials. In the last years she has been strongly related to the development of ODS Fe-Cr alloys for fusion applications. Her research interest lies in correlating the processing parameters with the mechanical properties, microstructure and nanostructure of the obtained materials and their evolution after irradiation. In July 2013 she joined the Materials for Fusion and Fission project as a Postdoctoral Research Assistant in collaboration with the Atom Probe group.

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Dr Daniel Haley

Dr Daniel Haley

Postdoctoral Research Assistant

The Development of an in-situ Deuterium Charging Cell for
Atom Probe Analysis of Hydrogen embrittlement in Metals

daniel.haley@materials.ox.ac.uk

Daniel is a post-doctoral researcher currently investigating hydrogen imaging via Atom probe, as part of the Hydrogen Embrittlement in Metals (HEMs) project. Daniel initially conducted APT-based hydrogen studies at the Max-Planck Institut für Eisenforschung in Düsseldorf, Germany.

The atom probe component of the HEMs project aims to develop hydrogen imaging in APT to a straightforward method for imaging hydrogen in steels (and other materials), to better understand the ubiquitous role of hydrogen in toughness reduction.

Daniel also works in the area of atom probe data analysis, with his previous time in Oxford working on new atom probe reconstruction methods, based upon physical models of evaporation coupled to experimental data.

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Andrew London

Dr Andrew London

Post Doctoral Research Assistant

Spatial Distribution and Irradiation Response
of Oxide-Dispersed Steels

andrew.london@materials.ox.ac.uk

Low activation steels are promising candidates for future fission and fusion reactors but lack the high temperature stability required for long-term use. One way of reinforcing these materials is to introduce nano-scale oxide inclusions which block dislocation glide. Andrew is investigating the chemical influence of alloy composition on the irradiation stability of model alloys produced in collaboration with the Indira Gandhi Centre for Atomic Research in India. Andrew is using atom probe tomography to study the spatial distribution, character and irradiation response of the yttrium-titanium rich oxides in these steels to further the fundamental understanding of these types of alloys.

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Dr Tomas Martin

Dr Tomas Martin

Atom Probe Group Lab Manager

Phone: +44 (0) 18652 73694

tomas.martin@materials.ox.ac.uk

Tomas manages the LEAP instruments and lab. In addition to general maintenance of the atom probe instruments, Tomas is the lead contact for the group's commercial and academic partners. As part of this process he is responsible for the preparation and analysis of specimens for collaborations including with Cambridge, Manchester, Swansea, Bristol and Stockholm universities and commercial institutions including AWE, Rolls Royce and Tata Steel. Tomas has experience preparing and analysing a wide variety of materials for atom probe including various steel, uranium, nickel, cobalt, titanium and zirconium alloys, as well as semiconductors such as silicon, GaN, InAlN and diamond.

Tomas completed his PhD at the University of Bristol in 2011, using density function theory calculations and electron photoemission spectroscopy to study negative electron affinity surfaces on diamond. Negative electron affinity surfaces, where the conduction band sits above the vacuum level, offer huge potential for new high yield electron emission devices. The lithium-oxygen surface termination discovered during Tomas' PhD was patented in 2012. In addition to his academic work, Tomas is managing editor of the Elsevier journal Materials Today Communications.

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Stella Pedrazzini

Dr Stella Pedrazzini

Postdoctoral Research Assistant

Atomistic scale characterisation of Radiation Damage in
Tuned Perovskites for Nuclear Applications

Phone: +44 (0) 1865 73634

stella.pedrazzini@materials.ox.ac.uk

 

Stella joined the group in April 2014 as a post-doctoral research assistant and part of an EPSRC funded collaboration between the Universities of Oxford, Sheffield, Liverpool and  Huddersfield, Imperial College London and Oak Ridge National Laboratory (Tennessee). Her research uses mainly Atom Probe Tomography as an analytical tool to assess environmental degradation of perovskite superconductors after exposure to radiation. She also uses a variety of complementary techniques, which include SEM, FIB, TEM, EBSD, XRD and synchrotron-based GIXD to achieve a more comprehensive understanding of irradiation effects in perovskites.

Stella completed her PhD from the University of Oxford in March 2014, focussing on the production, characterisation and mechanical properties of bulk nanostructured Al-based composites for high temperature applications. Her interest in materials with aerospace applications continues to this day. In addition to her own research project, she works on a number of consultancy jobs characterising both environmental degradation and microstructural alterations as a result of mechanical damage in Ni-based superalloys, sponsored by industrial collaborators Rolls-Royce plc., Siemens, Goodfabs and more.

Stella's list of publications can be found here.

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Visiting Academics


Paul Bagot

Dr Paul Bagot

Visiting Academic

Phone: +44 1865 273711

paul.bagot@materials.ox.ac.uk

 

One of Paul's main research interests is heterogeneous catalysts, where he is interested in understanding the fundamental interactions of catalytic metals under realistic operating environments. This uses APT and other high resolution techniques to examine surface segregation effects that markedly change catalyst performance. Alongside this, he is exploring novel sample preparation methods for APT to look at “engineered nanoparticles”, specifically core-shell systems consisting of a layer of metal atoms surrounding an interior of a different metal. By carefully controlling the atomic-scale structure of these it is possible to greatly improve catalyst performance by often using alternative metals, which is critical considering the cost and availability of many Pt-group elements in use.

 

A second area Paul works on is advanced engineering alloys for aerospace and related applications. These involve Ti-alloys, Ni-superalloys and Co-alloys, all of which have highly complex microstructures. Aside from using APT to characterize the as-processed forms of these, a major aim of this work is to identify how operating conditions can alter them, which is vitally important to predict failure routes and to fine-tune compositions. This work involves a wide range of techniques including APT, SEM, 3D-FIB and XPS in order to fully understand the changes. Paul is involved in developing in-situ reaction cells for the latest generation APT instruments (in collaboration with ISU) in order to use APT to explore oxidation behaviours in these alloys, and am working alongside Rolls-Royce in a Royal Academy of Engineering Industrial Secondment to exploit these techniques.

 

The third theme Paul works on is as part of the Materials for Fusion and Fission, a wide-ranging collaboration between a number of institutions/industrial partners to design, produce and test potential materials for new nuclear installations. The focus of this work is advanced W-alloys for plasma facing components and oxide dispersion strengthened steels for structural components, both of which need to withstand extremely hostile operating environments. APT experiments on post-ion irradiated materials can accurately identify microstructural changes that predicate the onset of potential issues.

 

Dr Paul Bagot - Materials Oxford Homepage (with summary of research interests and full list of publications)

 

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Dr Baptiste Gault

Visiting Academic, Max Planck Institute fur Eisenforschung

baptiste.gault@materials.ox.ac.uk

After a PhD mixing physics and materials science in France (University of Rouen, 2006) focused on the development of the pulsed-laser atom probe microscope, I have successively been a research scientist at The Australian Centre for Microscopy & Microanalysis at The University of Sydney, a Marie Curie postdoctoral fellow at the Department of Materials of the University of Oxford, a research scientist at The University of Sydney (again) on a joint position with the Australian Nuclear Science & Technology Organisation, and finally an assistant professor at McMaster University in Canada. I started at Elsevier Ltd. in a role of Publisher in Dec. 2012, where I manage a portfolio of journals in Materials Science. Although currently a full-time group leader at MPIE, I gladly accepted the honorary title of Visiting Academic of the Department of Materials, so I can keep collaborating and provide help and support to the group.

Dr Jonathan Hyde

Visiting Academic, National Nuclear Laboratory

jonathan.hyde@materials.ox.ac.uk

Extensive research on ferritic steels used to manufacture reactor pressure vessels (RPVs) has demonstrated that irradiation-induced damage can be classified as a combination of matrix damage resulting from radiation produced point defect clusters and their radiation enhanced formation of 1–2 nm diameter clusters containing solutes such as Cu, Mn, Ni and Si. Despite the size of these features, they can have a dramatic and deleterious effect on materials properties. The irradiation-induced features act as barriers to dislocation movement resulting in an increase in hardness which results in embrittlement. Microstructural characterisation, using atom probe tomography, is imperative because it underpins the mechanistic understanding of the damage processes which is essential for predicting materials properties at higher doses or in materials of different composition. The main focus of Dr Hyde's current research is the characterisation of the very early stages of solute clustering. This is an area of increasing interest on two counts:

  • the mechanisms of cluster formation are poorly understood
  • there is new evidence for late blooming phases (LBPs), which is an increasing concern as plant operators are looking to extend plant life beyond the original design life of the RPV. There is a need to ensure methodologies are in place to detect the early stages of LBPs.

In addition, Dr. Hyde is interested in developing improved algorithms for characterising small solute clusters and precipitates.

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Research Students

 


Michal Dagan

Megan Carter

Masters student

Aluminium alloys for automotive applications

megan.carter@materials.ox.ac.uk



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James Douglas

James Douglas

DPhil student

Atom Probe Tomography Characterisation
of Phosphorus Implantation and Iron Gettering
in Silicon

Phone: +44 (0) 1865 273634

james.douglas@materials.ox.ac.uk

With the introduction of laser pulsing as a method of initiating field evaporation in non-conductive materials and advances in Focussed Ion Beam (FIB) specimen preparation, atom probe tomography (APT) of semiconductor materials and semiconductor devices is now a growing area of research. Using the chemical and spatial atomic information obtained from APT, I am investigating the distribution of impurities in single crystal and multicrystalline silicon. In particular, I shall be focus on:

1) Implantation profiles of low energy, sub surface implanted phosphorus atoms with an aim to improve modelling and manipulation of nanoscale silicon architecture for new devices in conventional and quantum computing. This is in collaboration with Professor David Jamieson of the University of Melbourne’s Centre for Quantum Computation & Communication Technology.

2) The mechanisms of phosphorus diffusion gettering of transition impurities in multicrystalline silicon used for industrial scale solar cell manufacturing, these are known to act as recombination centres and reduce device efficiency. Changes in iron distribution and concentration with varying phosphorus dopant concentrations and thermal processing will be investigated. This project is in collaboration with Profefssor John Murphy of the University of Warwick.

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Anne Callow

Anne Callow

DPhil student

Hydrogen Pickup and Oxidation in
Zirconium Alloys for Nuclear Fuel Cladding

anne.callow@materials.ox.ac.uk


 

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Qifeng Yang

 

Qifeng Yang

DPhil student

Atom Probe Analysis of Nanoparticle Catalysts

qifeng.yang@materials.ox.ac.uk

Catalytic alloys are of paramount importance in chemicals production, pollution control and generation of clean energy using fuel cells. The structure and chemical information of such catalytic alloys are a long lasting research area in terms of improving understanding of the link between structure and performance, with the overall aim of producing more efficient catalysts using less expensive rare metals. Novel techniques are increasingly involved in this work.  Atom probe tomography (APT), which has high spatial resolution and mass resolution, has been proved as an important technique to evaluate catalytic alloys.

In my research, APT will be utilized to study model bimetallic alloys and a range of core-shell type catalytic particles. The surface segregation of metals in a catalyst is an important aspect of this research. Metallic behaviours of catalytic alloys under different temperatures and atmospheres will be investigated via APT to further understand issues such as performance loss/catalyst poisoning.

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Yeli Guma

Guma Yeli

DPhil student

The Effects of Thermal Ageing on Fission Reactor Component Steels

guma.yeli@materials.ox.ac.uk

Iron-based alloys are core class of structural materials for nuclear reactors because of their good combination of high strength, corrosion resistance and a degree of ductility and toughness. Unfortunately, carefully these carefully selected properties can change during long term service.  This study is focused on the thermal aging effects of iron-based alloys utilizing atom-probe tomography. Micro structural changes including clustering and phase-separation will be analysed using this method, while complementary hardness tests will be made to link atomic-scale changes with mechanical properties. A model will also be developed to predict the mechanical properties.

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David Tweddle

DPhil student

Atom Probe Characterisation of Individual Dislocations in Multi-Crystalline Silicon

david.tweddle@materials.ox.ac.uk

 

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Tom Lapington

Tom (Mark) Lapington

DPhil student

High resolution characterization of oxidation
mechanisms in nickel-based superalloys

mark.lapington@materials.ox.ac.uk

Tom joined the group in October 2014 following completion of a degree in engineering at the University of Swansea. His DPhil research will be carried out on the oxidation behaviour of new prototype polycrystalline nickel-based superalloys, for use in high-temperature turbine disc applications. The emphasis will be on establishing compositional effects related to small additions of elements such as Al, Cr, Co, Nb and Ti on Oxidation behaviour. Both bulk oxidation and oxidation at crack tips – for example during dwell fatigue – will be considered. Atom-probe Tomography will be used to study the compositional variations on the atomic scale, whilst Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and electron microscopy will be utilized for larger scale bulk characterization purposes.

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Yi-Sheng Chen

Yi-Sheng Chen

DPhil student

Hydrogen embrittlement in steels and
deuterium charging of metals for APT analysis

yi-sheng.chen@materials.ox.ac.uk

Yi-Sheng Chen completed his BS and MS at National Tsing Hua University in Taiwan and then joined the group for the project of investigating hydrogen imaging via Atom Probe, as part of HEmS (Hydrogen in metals - from fundamentals to the design of new steels). It has been known for over a hundred years that hydrogen causes catastrophic failure in high strength steels. The overall aim of HEmS is to provide a comprehensive understanding of the process of hydrogen embrittlement in steels, through an integration of advanced characterisation, testing and modelling techniques. This new understanding will be used to develop new ultra-high strength steels that are resistant to embrittlement in the presence of hydrogen. Our sub-work package will implement Atom Probe Microscope to provide atomic scale physical and chemical analysis, including local bonding information, by using deuterium charged samples. This method of characterising hydrogen/deuterium in steels will improve our understanding of the origin of hydrogen embrittlement and elucidate the mechanisms of hydrogen trapping.

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Benjamin Jenkins

Benjamin Jenkins

DPhil student

Clustering in RPV steels: an Atom Probe study

benjamin.jenkins@materials.ox.ac.uk

 The reactor pressure vessel (RPV) is often considered the limiting factor in achieving long-term operation for commercial light water reactor nuclear power plants.

 
Solute clustering is known to play a significant role in the embrittlement of RPV steels. Primarily, research has focused on the deleterious effects of copper. Recent research has also focused on the effects of nickel and manganese.
 
My project is a continuation of work conducted by Jenni Zelenty, and focuses on the effects of long-term thermal ageing on the microstructure and mechanical properties of RPV steels. Atom probe tomography (APT) is utilised to characterise the early stage clustering of nickel, and manganese within low copper RPV steels.
 
To date the steels have been thermally aged for 10,000 hours at various temperatures (330°C, 365°C, and 405°C). As the steels age, hardness tests will be conducted and samples will be analysed using APT in order to investigate the solute clustering mechanisms induced by the ageing process.

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Hazel Gardner

DPhil student

Atom probe analysis of Ti-based alloys

hazel.gardner@materials.ox.ac.uk

 

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Visiting student (RWTH Aachen)

alexander.gramlich@materials.ox.ac.uk

Alexander Gramlich is a project student from RWTH Aachen, currently working with Prof Michael Moody and Dr Maria Auger on steel for USC applications.

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