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arXiv · 2603.19592

Non-collinear ferromagnetism in the Kondo lattice Ce$_5$CoGe$_2$

Jinyu Wu·Jiawen Zhang·Toni Shiroka·Shams Sohel Islam·Mingyi Wang·Yongjun Zhang·Devashibhai T. Adroja·Yu Liu·Huiqiu Yuan·Michael Smidman
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Abstract

The dense Kondo lattice Ce$_5$CoGe$_2$ exhibits superconductivity once the magnetic ordering is suppressed by pressure. Here the ambient pressure magnetic state is investigated via magnetization, heat capacity, powder neutron diffraction, and muon spin relaxation ($\mu$SR) measurements. Neutron diffraction results reveal a noncollinear ferromagnetic structure, where the four inequivalent Ce sites exhibit different magnetic moments. Point-charge model calculations of the crystalline-electric field (CEF) ground states corroborate different moments between the sites, and suggest sizeable components of the moments along different directions, consistent with the non-collinear structure. Analysis of the Dzyaloshinskii-Moriya (DM) interaction for the bonds connecting Ce atoms demonstrates that most of these bonds exhibit a nonzero DM vector, suggesting that competition between intersite magnetic exchange interactions, CEF driven single-ion anisotropy, the Kondo effect and the DM interaction may drive the non-collinear ferromagnetism.

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Jinyu Wu, Jiawen Zhang, Toni Shiroka, Shams Sohel Islam, Mingyi Wang, Yongjun Zhang, Devashibhai T. Adroja, Yu Liu, Huiqiu Yuan, Michael Smidman. 2026-03-20. Non-collinear ferromagnetism in the Kondo lattice Ce$_5$CoGe$_2$. https://doi.org/10.1103/r1qt-9pkk

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