Influence of Strain and Applied Field on the L10 Atomic Ordering and Subsequent Hard Magnetic Properties of Near-Equiatomic FeNi
Date:
Contributed talk at the 2025 Joint MMM-Intermag Conference.
Abstract
The ever-growing demand for advanced permanent magnets is accompanied by a pressing need for materials of reduced critical element content, including rare earth elements, which carry concerns around price volatility, geopolitical sensitivities, and significant environmental impact. One rare-earth-free magnetic material of current interest is atomically ordered FeNi [1], which crystallizes in the L10 structure and is commonly referred to by its meteoritic mineral name, tetrataenite [2]. However, a low atomic ordering temperature and consequently sluggish kinetics make this material challenging to synthesize in industrially relevant timeframes. Here, new results dervied from first-principles computational approaches will be presented examining the combined impacts of mechanical strain, applied magnetic field, and varying Fe:Ni ratio on the L10 ordering temperature of this material (Fig. 1). These results are in alignment with recent experimental outcomes reporting induced atomic order in bulk specimens, given suitable processing conditions [3]. Our DFT-based methodology [4,5] enables holistic modelling of both atomic ordering and associated magnetocrystalline anisotropy—including the effects of finite temperature —within the same computational framework. These results suggest new routes by which bulk synthesis of this material could potentially be achieved.
References
[1] L. Neel et al., J. Appl. Phys. 35, 873 (1964).
[2] L. H. Lewis et al., J. Phys.: Condens. Matter 26, 064213 (2014).
[3] L. H. Lewis, P. S. Stamenov, Adv. Sci. 2302696 (2023).
[4] C. D. Woodgate et al., J. Appl. Phys. 134, 163905 (2023).
[5] C. D. Woodgate et al., npj Comput. Mater. 10, 272 (2024).
Acknowledgments
Research supported by the U.S. Department of Energy, Office of Basic Energy Sciences under Award Number DE SC0022168 (for atomic insight) and by the UK Engineering and Physical Sciences Research Council, Grant No. EP/W021331/1 and the U.S. National Science Foundation under Award ID 2118164 (for advanced manufacturing aspects).