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Giant magnetocrystalline anisotropy energy in Fe-Co alloy under uniaxial compression: A first-principles prediction

Wojciech Marciniak*

José Ángel Castellanos-Reyes

Joanna Marciniak

Mirosław Werwiński†

  • *Contact author: wojciech.fil.mk@gmail.com
  • †Contact author: werwinski@ifmpan.poznan.pl
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Phys. Rev. B 114, 204404 – Published 5 October, 2026

DOI: https://doi.org/10.1103/trb5-yktf

Abstract

Uniaxially strained Fe-Co disordered alloys have emerged as promising candidates for cost-effective (especially Fe-rich alloy), high Curie temperature (both Fe-rich and Co-rich), rare-earth-free permanent magnets due to their high magnetocrystalline anisotropy energy (MAE). Using first-principles, fully relativistic calculations within the coherent potential approximation and Perdew-Burke-Ernzerhof exchange-correlation potential, we explore the MAE of tetragonal Fe-Co alloys under uniaxial compression. Our results reveal a previously uncharted region of high MAE (exceeding 3MJm−3) accessible via uniaxial compression. This phase, which lies between hexagonal-close-packed and body-centered-cubic structures, exhibits a high magnetic moment and Curie temperature, and thus offers a more stable candidate for experimental realization than the currently known high-MAE uniaxially strained Fe-Co.

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Phys. Rev. B 114, 204404– Published 5 October, 2026
  • Received 30 October 2024
  • Revised 31 August 2026
  • Accepted 3 September 2026
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