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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 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 Maths and Physics at the University of Warwick, graduating in 2019 with 1st class honours (BSc MMathPhys). My final year project supervisor was Dr Nicholas d'AmbrumenilLink opens in a new window; we looked at some aspects of the physics of the frustrated antiferromagnetic system of Gadolinium Gallium Garnet.

Research Interests

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

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 KKR-CPA calculations, a linear response theory, and atomistic simulations. 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 predictions for short-range order in these systems were 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 the refractory metals: V, Nb, Mo, Ta, W. Again, we demonstrated the effectiveness of our approach in understanding the nature of SRO in these systems. In a progression of the project, we also studied the effect of magnetic order on atomic order in the 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 materials.

At present, we are studying a number of multicomponent alloy systems in collaboration with the Nanomagnetism Group of of Prof. Laura H. LewisLink opens in a new window in the Department of Chemical Engineering at Northeastern UniversityLink opens in a new window, with an overarching view of searching for candidate materials for good permanent magnets which use reduced concentrations of rare-earth elements. 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 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.

PhD Thesis

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

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

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.

Portrait

Contact Details:

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

Office: PS1.29