Influence of topology on the phase transition of a ferromagnetic metal
Citation:
Rui Zhang, Yangkun He and J. M. D. Coey, Influence of topology on the phase transition of a ferromagnetic metal, Proceedings of the National Academy of Sciences, 120 (36), 36, 2023, e230246612 - 1-6Download Item:
Abstract:
The topological ferromagnet CoS2 exhibits an anhysteretic, weakly first-order transition at the Curie temperature of 119.8 K with a tricritical point µ0Htcp at 0.034 T. Magnetic symmetry and the mixing of majority and minority spin eg bands at a subband crossing just above the Fermi level produce a topological component of the magnetization that leads to a negative M3 term in the Landau free energy. The position of the Fermi level relative to the subband crossing is critical for controlling the order of the transition. Hole doping in Co0.89Fe0.11S2 drains the minority-spin eg pocket and results in a normal second-order phase transition. Electron doping in Co0.94Ni0.06S2 raises the Fermi level toward the subband gap, producing a strongly first-order transition with 15 K hysteresis. Our results demonstrate a relation between topological electronic structure and thermal hysteresis at the Curie point, which may help in the search for magnetocaloric materials.
Sponsor
Grant Number
Science Foundation Ireland (SFI)
ZEMS (16/IA/4534)
National Natural Science Foundation of China (60703033).
Grants No. 12204383
Novo Nordisk Foundation
Author's Homepage:
http://people.tcd.ie/venkatemhttp://people.tcd.ie/jcoey
Description:
PUBLISHED
Author: Coey, John
Sponsor:
Science Foundation Ireland (SFI)National Natural Science Foundation of China (60703033).
Novo Nordisk Foundation
Type of material:
Journal ArticleCollections
Series/Report no:
Proceedings of the National Academy of Sciences120 (36)
36
Availability:
Full text availableKeywords:
Landau theory, First-order phase transition, Magnetocaloric materials, Topological ferromagnet, Tricritical pointSubject (TCD):
Nanoscience & Materials , Condensed matter, electronic, magnetic and superconductive properties , Magnetism and spin electronics , NanotechnologyDOI:
https://doi.org/10.1073/pnas.2302466120Source URI:
https://doi.org/10.1073/pnas.2302466120ISSN:
0027-8424Metadata
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