Interplay Between Magnetism and Short-Range Order in Ni-Based High-Entropy Alloys: CrCoNi, CrFeCoNi, and CrMnFeCoNi
Date:
Contributed poster at the Joint European Magnetic Symposia 2023.
Abstract
We suggest a potential route for tuning atomic ordering in medium- and high-entropy alloys, by annealing samples in an applied magnetic field and thus altering the magnetic state. Controlling atomic order is critical for tuning materials properties, and our approach could open up new routes for discovery of novel materials. Specifically, the impact of magnetism on predicted atomic short-range order in Ni-based high-entropy alloys is studied using a first-principles, all-electron, Landau-type linear response theory, coupled with lattice-based atomistic modelling [1,2]. We perform two sets of linear-response calculations: one in which the paramagnetic state is modelled within the disordered local moment picture, and one in which systems are modelled in a magnetically ordered state. We show that the treatment of magnetism can have significant impact both on the predicted temperature of atomic ordering and also the nature of atomic order itself [3]. In CrCoNi, we find that the nature of atomic order changes from being L12-like when modelled in the paramagnetic state to MoPt2-like when modelled assuming the system has magnetically ordered. In CrFeCoNi, atomic correlations between Fe and the other elements present are dramatically strengthened when we switch from treating the system as magnetically disordered to magnetically ordered. Our results show it is necessary to consider the magnetic state when modelling multicomponent alloys containing mid- to late-3d elements, and we suggest that, potentially, there could be a variety of multicomponent alloy compositions containing 3d transition metals that will exhibit specific atomic ordering when thermally treated in an applied magnetic field.
Acknowledgements
We gratefully acknowledge the support of the UK EPSRC, Grant No. EP/W021331/1. C.D.W. is supported by a studentship within the UK EPSRC-supported Centre for Doctoral Training in Modelling of Heterogeneous Systems, Grant No. EP/S022848/1. This work was also supported in part by the U.S. Department of Energy, Office of Basic Energy Sciences under Award Number DE SC0022168 and by the U.S. National Science Foundation under Award ID 2118164.
References
[1] C. D. Woodgate and J. B. Staunton, Phys. Rev. B 105, 115124 (2022).
[2] C. D. Woodgate and J. B. Staunton, Phys. Rev. Mater. 7 013801 (2023).
[3] C. D. Woodgate D. Hedlund, L. H. Lewis, J. B. Staunton, arXiv:2303.00641 (2023)