Personality of a magnet: Simulating chemical ordering in FeNi at the atomic and sub-atomic length scales
Date:
Contributed talk at Isambard Day 2025, a high-performance computing (HPC) conference organised by the Bristol Centre for Supercomputing (BriCS).
Abstract
Permanent magnets are ubiquitous in our modern, electrified society. The most lightweight and efficient electrical motors and generators are those using hard magnetic materials, i.e. permanent magnets, to provide the magnetic fields necessary to convert between electrical and mechanical forms of energy. Driven by the emergent climate crisis, the transition away from the burning of fossil fuels and towards sustainable sources of energy is resulting in increased demand for permanent magnets for use in renewable energy technologies.
However, there are currently relatively few suitable, commercially viable permanent magnetic compounds with intrinsic physical properties good enough to be useful in advanced engineering applications. Moreover, those compounds which are suitable for such applications often contain significant quantities of rare-earth elements such as Sm, Nd, Tb, and Dy, in addition to other critical minerals such as Co. There is therefore a desire to investigate new, sustainable permanent magnetic materials which could facilitate diversification of the supply chain.
This talk will focus on a candidate rare-earth free ‘gap’ magnet, FeNi, which crystallises in the tetragonal L10 structure. Recent efforts to model the hard magnetic properties [1] and crucial chemical disorder-order transition [2] in this material will be discussed. Preliminary results from development of a machine-learned interatomic potential for assessment of vacancy migration barriers and atomic self-diffusion coefficients in the alloy [3], facilitated by a Technical Preparatory Project on the Isambard 3 platform, will also be presented.
References
[1] Woodgate, Patrick, Lewis, Staunton, J. Appl. Phys. 135, 163905 (2023).
[2] Woodgate, Lewis, Staunton, npj Comput. Mater. 10, 272 (2024).
[3] Fisher, Staunton, Wu, Brommer, Modelling Simul. Mater. Sci. Eng. 32, 065024 (2024).
Acknowledgments
Support is acknowledged from the UK Engineering and Physical Sciences Research Council, the US Department of Energy, and the US National Science Foundation.