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ESR investigations of the magnetic anisotropy in $κ − {(BETS)}_{2} Mn {[{N (CN)}_{2}]}_{3}$

Zhijie Huang¹, Marvin Schmidt ¹, Savita Priya¹, Mark Kartsovnik ², Natalia Kushch³, and Martin Dressel ¹

¹1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
²Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, D-01328 Dresden, Germany
³Federal Research Center of Problems of Chemical Physics and Medical Chemistry, Russian Academy of Sciences, 142432 Chernogolovka, Russia

Phys. Rev. B 113, 035137 – Published 21 January, 2026

DOI: https://doi.org/10.1103/ly9b-x7ct

Abstract

The two-dimensional molecular conductor $κ − {(BETS)}_{2} Mn {[{N (CN)}_{2}]}_{3}$ has been studied because of the intriguing magnetic coupling of the molecular $π$ electrons to the ${Mn}^{2 +}$ ions. Utilizing X-band electron spin resonance spectroscopy we have performed comprehensive investigations of the magnetic properties, in particular on the temperature and angular dependences of the spin susceptibility, the $g$ factor, and the linewidth. Due to the $π - d$ coupling, a rearrangement of the $π$ spins occurs: At low temperatures the $g$ factor shifts enormously with a pronounced in-plane anisotropy that flips as the temperature decreases, the lines broaden significantly, and the spin susceptibility increases upon cooling with a kink at the phase transition. By carefully analyzing the angular dependence of $g (θ)$ and $Δ H (θ)$ we reveal the influence of anisotropic Zeeman interaction in addition to spin-phonon coupling. We conclude the presence of two magnetically distinct BETS chains and discuss the possibility of altermagnetic order.

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References (50)

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Phys. Rev. B 113, 035137– Published 21 January, 2026

Vol. 113, Iss. 3 — 15 January 2026

Received 5 September 2025
Revised 17 December 2025
Accepted 5 January 2026

DOI: https://doi.org/10.1103/ly9b-x7ct

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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ESR investigations of the magnetic anisotropy in $κ − {(BETS)}_{2} Mn {[{N (CN)}_{2}]}_{3}$

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ESR investigations of the magnetic anisotropy in κ−(BETS)2Mn[N(CN)2]3

Abstract

Physics Subject Headings (PhySH)

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References (50)

ESR investigations of the magnetic anisotropy in $κ − {(BETS)}_{2} Mn {[{N (CN)}_{2}]}_{3}$