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  • Open Access

Why Fe3GaTe2 has higher Curie temperature than Fe3GeTe2

Bomin Kim1, Tumentsereg Ochirkhuyag2, Dorj Odkhuu2,*, and S. H. Rhim1,†

  • *Contact author: odkhuu@inu.ac.kr
  • †Contact author: sonny@ulsan.ac.kr
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Phys. Rev. Research 8, 023333 – Published 24 June, 2026

DOI: https://doi.org/10.1103/g4v8-mrnd

Abstract

Physics of Fe3GaTe2 having higher Curie temperature (TC) than Fe3GeTe2 is explored theoretically in the framework of magnetic exchange interactions. Fe3GaTe2 and Fe3GeTe2 are isostructural, with Fe3GaTe2 having one less valence electron and smaller nearest-neighbor exchange coefficients (J1 and J2), challenging the conventional notion that larger J1 or J2 leads to a higher TC. Based on the hybridization exchange, we show that higher-order exchange coefficients (J3 or higher) are positive for Fe3GaTe2 but negative for Fe3GeTe2, due to a one-electron difference. As a consequence, total sum of all possible exchange coefficients in Fe3GaTe2 are larger than that for Fe3GeTe2, which accounts for higher TC. To validate these findings, TC values are computed using both mean-field theory and Monte Carlo simulation. Indeed, higher-order exchange interactions, when properly accounting for the number of neighbors, confirm the higher TC of Fe3GaTe2.

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Phys. Rev. Research 8, 023333– Published 24 June, 2026
  • Received 20 January 2025
  • Revised 17 April 2025
  • Accepted 26 May 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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