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EPSRC CDT in Modelling of Heterogeneous Systems - HetSys

Christopher Woodgate

PhD Title: Physics of magnets and the arrangements of atoms comprising them

PhD Supervisor: Prof. Julie B. StauntonLink opens in a new window

I anticipate that from October 2023 I will have limited access to this official Warwick page following submission of my PhD thesis and subsequent move to a new postdoc position. My personal site, chriswoodgate.github.ioLink opens in a new window, will be a more reliable and up-to-date source of information.

Background

As an undergraduate, I studied Mathematics and Physics (BSc MMathPhys) at the University of Warwick, graduating in 2019 with first class honours. My final year project supervisor was Dr Nicholas d'AmbrumenilLink opens in a new window. We looked at some aspects of the physics of Gadolinium Gallium GarnetLink opens in a new window, which is an intriguing, geometrically frustrated magnetic system.

During the course of my undergraduate studies, I also undertook a Summer research project in the Elementary Particle Physics group under the supervision of Dr Michal KrepsLink opens in a new window, where I worked on a study examining the feasibility of measurement of the Ξb production polarisation at the LHCb experimentLink opens in a new window, which is one of the experiments collecting data at the Large Hadron Collider at CERN. This project was supported by a Warwick Undergraduate Research Support Scheme (URSS)Link opens in a new window bursary.

Research Interests

I am now in the fourth and final year of the HetSys programme, working under the supervision of Prof. Julie B. StauntonLink opens in a new window. We study the physics of multicomponent alloys, using electronic structure calculations and atomistic modelling to predict the nature of atomic arrangements in these systems. We then go on to study the effect of these atomic arrangements on materials properties, with a particular focus on magnetic properties.

Initially we looked at the binary alloy Fe1-x Gax , commonly referred to as 'Galfenol'. This is a highly magnetostrictive material and has applications in the design of sensors and actuators. I studied the nature of atomic ordering in the material which, in collaboration with Dr George MarchantLink opens in a new window, we used to explain the Ga-concentration dependence of the material's magnetoelastic constant.

We then moved on to looking at the nature of atomic short range order in multi-component alloys, with a particular focus on the so-called 'high-entropy alloys' (HEAs). We use a combination of density functional theory (DFT) calculations, the coherent potential approximation (CPA), a linear response theory, and atomistic simulations to model the phase stability of these materials. In a recent paper we were able to demonstrate the effectiveness of our approach by studying the prototypical equiatomic HEA, CrMnFeCoNi and its derivatives, collectively referred to as the Cantor-Wu alloys. Our predicted atomic short-range order (ASRO) in these systems was in excellent agreement with existing experimental and theoretical literature for very low computational cost. Following on from this successful work, we then looked at another family of HEAs, based on refractory metals: V, Nb, Mo, Ta, W. Again, we demonstrated the effectiveness of our approach in understanding the nature of ASRO in these systems. In a progression of the project, we also studied the effect of magnetic order on atomic order in Ni-based HEAs, shedding light on some open questions within the materials modelling community. It is our hope that our newly-developed approach can, in future, be used for materials discovery in the vast space of multicomponent alloys and, more generally, high-entropy compounds.

At present, we are studying a number of multicomponent alloy systems in collaboration with the Nanomagnetism Group of Prof. Laura H. LewisLink opens in a new window in the College of Engineering at Northeastern UniversityLink opens in a new window, Boston, USA. Our focus is on searching for candidate materials for good permanent magnets which use reduced concentrations of rare-earth elements. These rare-earth-free and rare-earth-lean magnets have the potential to be used in a range of technologies, including in electrical power generation and electric motors, essential technologies in the global transition to a low-carbon future. The Northeastern group are experimentalists working on novel synthesis techniques for magnetic materials, and it is our hope that our computational modelling will help guide materials synthesis and processing to enhance desirable magnetic properties.

Publications

A list of my publications can also be found on my Google Scholar profileLink opens in a new window, or via my ORCIDLink opens in a new window.

Book

I have authored a book outlining our approach for modelling atomic arrangements in multicomponent alloys, which was published by Springer Nature in August 2024 as part of the Springer Series in Materials ScienceLink opens in a new window. It represents an enlarged and extensively reworked version of my doctoral thesis, including new results and additional commentary. Full details are available via this linkLink opens in a new window, and the book cover is shown below.

Cover for 'Modelling Atomic Arrangements in Multicomponent Alloys: A Perturbative, First-Principles-Based Approach'

PhD Thesis

My PhD thesis is available on the Warwick research archive portal (WRAP):

Prizes and Awards
  • Winton Thesis Prize in Physics - May 2024.
    • Awarded annually by the Department of Physics at the University of Warwick for an outstanding PhD thesis examined in the previous calendar year.
Talks and Conference Presentations

  • “Short-Range Order in High-Entropy Alloys: First Principles Theory and Atomistic Modelling”, Theory of Condensed Matter 2022 (Institute of Physics), Coventry, UK, June 2022. Contributed poster. Poster Link opens in a new window

Outreach and Public Engagement

I was the lead host for the first series of the HetSys podcast series, Multiscale MusingsLink opens in a new window, and for the second series I took on a leadership role. We interviewed academics with research interests in the area of predictive modelling, talking to them about their hobbies and interests, and also details of their research. The podcast is aimed at a general audience.

I am also involved with the Computational Toolkit seminar seriesLink opens in a new window, which is aimed at undergraduates, PhD students, and early-career researchers looking to develop a career in computational science.

Finally, I have experience of running sessions for work-experience students from local schools, introducing them to the kinds of problems computational physicists work with on a day-to-day basis!

Hobbies and Interests

I am heavily involved with the University of Warwick Archery ClubLink opens in a new window. In the past I have held the committee positions of Club Secretary (2021/22), Equipment Officer (2019/20, 2020/21), and Team Captain (2016/17). I enjoy both the competitive and social aspects of the sport, and am also a qualified Archery GB Level 2 coach.

I also enjoy the (rather old-fashioned) tradition of English-style change ringingLink opens in a new window. I am Steeple Keeper at All Saints Church, Leamington Spa, and also a member of the Association of Ringing Teachers (ART)Link opens in a new window.

Portrait

Contact Details:

E-Mail:
C.Woodgate"at"warwick.ac.uk

christopher.woodgate"at"physics.org

Office: PS1.29