2026/08/03 by U. Miniotaite, O. K. Forslund, H. Luetkens +8
Physics and Astronomy · #cond-mat.str-el
13 pages total (8 pages main text, 5 pages appendix and references), 7 Figures
arxiv created 2026/08/03 · arxiv updated 2026/08/04
We report a comprehensive muon spin relaxation (μ+SR) and bulk magnetization study of the antiferromagnetic (AFM) Weyl semimetal Mn3Sn (composition Mn2.99Sn). Mn3Sn is reported to exhibit a commensurate inverse triangular (IT) AFM phase, an incommensurate (IC) helical AFM phase, and a proposed low-temperature spin-glass-like state. In our sample, we establish the respective transition temperatures for these phases to be TN = 418 K, Tt ≈ 275 K, and Tf = 21 K. Investigating the low-temperature regime below Tf, we find no evidence of a static spin-glass state. Instead, the sample exhibits an increasing ferromagnetic (FM) component accompanied by a localized slowing of spin fluctuations, indicating that these phenomena may be decoupled. In the IC helical AFM phase, fitting the zero-field (ZF) spectra reveals an asymmetric internal magnetic-field distribution, indicating that the magnetic structure is heavily modified by anharmonicity. Upon warming above 150 K, a continuous redistribution of muon spectral weight reveals a broad regime of coexisting local magnetic environments associated with the IC helical and IT-AFM phases. In the commensurate IT-AFM phase above Tt, a persistent missing fraction in the initial asymmetry indicates that a subset of implanted muons, corresponding to roughly 20% of the sample-related asymmetry, undergoes unresolved ultrafast depolarization. Finally, we observe temperature-driven shifts in muon site populations above 325 K. Ultimately, our results show a highly dynamic magnetic landscape in Mn3Sn, demonstrating how its complex magnetic orders often coexist and evolve continuously with temperature.