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arXiv · 2501.05146

Polymorphism and Magnetism in a Kitaev Honeycomb Cobaltate KCoAsO$_4$

Yuya Haraguchi·Daisuke-Nishio Hamane·Hiroko Aruga Katori
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Abstract

We report the synthesis, crystal structure, and magnetic properties of a new Kitaev honeycomb cobaltate, KCoAsO$_4$, which crystallizes in two distinct forms: $P2/c$ and $R\bar{3}$ space groups. Magnetic measurements reveal ordering temperatures of $\sim$14 K for the $P2/c$ structure and $\sim$10.5 K for the $R\bar{3}$ structure. The $P2/c$-type KCoAsO$_4$ sample exhibits a complex temperature-field phase diagram, including a field-induced phase, while the $R\bar{3}$-type KCoAsO$_4$ shows a simpler phase diagram with a single magnetically ordered phase. The observed differences in magnetic properties are attributed to subtle structural variations, strongly suggesting that local structural changes play a crucial role in determining the magnetism of cobaltate-based Kitaev materials.

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Yuya Haraguchi, Daisuke-Nishio Hamane, Hiroko Aruga Katori. 2025-01-09. Polymorphism and Magnetism in a Kitaev Honeycomb Cobaltate KCoAsO$_4$. https://doi.org/10.1038/s41598-025-86302-6

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