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arXiv · 2403.19013

Antiferromagnetic domains in a single crystal of the A-type spin-7/2 trigonal topological insulator EuSn$_2$As$_2$

Santanu Pakhira·D. C. Johnston
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Abstract

EuSn$_2$As$_2$ is a trigonal A-type antiferromagnetic topological insulator with the moments aligned in the $ab$ plane and with a N\'eel temperature $T_{\rm N} = 23.5$ K. Here we report that an EuSn$_2$As$_2$ crystal exhibits a broad peak at $H_{\rm c1} = 1100$ Oe in the field derivative $dM_{ab}/dH$ of the $ab$-plane magnetization $M_{ab}(H)$ at temperature $T=2$ K, demonstrating the presence of trigonal antiferromagnetic domains. We model these $M_{ab}(H,\,T=2\,{\rm K})$ data and obtain the trigonal anisotropy-energy coefficient $K_3$ that is 13.3 and 3.7 times larger than those we previously reported for single crystals of the trigonal compounds EuMg$_2$Sb$_2$ and EuMg$_2$Bi$_2$, respectively.

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Santanu Pakhira, D. C. Johnston. 2024-03-27. Antiferromagnetic domains in a single crystal of the A-type spin-7/2 trigonal topological insulator EuSn$_2$As$_2$. https://arxiv.org/abs/2403.19013

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