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Effect of Co doping on structural and magnetic order in kagome magnet $TbF e_{6 - x} C o_{x} G e_{6}$ (nominal $x = 0 - 6$ )

Noah J. Fau ¹, Rahul Meduri¹, Atreyee Das ², Ryan E. Baumbach ², Gregory T. McCandless¹, and Julia Y. Chan ^1,*

¹Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, USA
²Department of Physics, University of California, Santa Cruz, Santa Cruz, California 95064, USA

^*Contact author: Julia_Chan@baylor.edu

Phys. Rev. Materials 10, 095002 – Published 10 September, 2026

DOI: https://doi.org/10.1103/my7d-txwd

Abstract

The kagome lattice motif has attracted interest for investigating the relationship between magnetic behaviors and topology. Materials containing two magnetic sublattices of distinct energy scales are known to induce spin frustration and tunable fire-ice ferrimagnetic states. Here we report the growth of single crystals of the kagome magnet $TbF e_{6 - x} C o_{x} G e_{6}$ (nominal $x = 0 - 6$ ). The substitution of Co into the Fe-based kagome lattice is accompanied by a structural transition from the more ordered $TbF e_{6} S n_{6}$ -type structure to the fully disordered $Y b_{0.5} C o_{3} G e_{3}$ -type structure. Reflections related to $TbF e_{6} S n_{6}$ -like superstructure ordering in single crystal x-ray diffraction images gradually dissipate with the addition of Co. Anisotropic magnetic measurements indicate an easy-plane (in-plane with the kagome slab) magnetic anisotropy in all members, as well as evidence of Tb ordering in the Co endmember. High-temperature magnetic susceptibility data indicates possible Co-doping induced suppression of magnetic ordering of the Fe sublattice. The progression of structural and magnetic order with Co doping enhances understanding of the evolution of stuffed CoSn structure types and the interplay between $f$ - and $d$ -block magnetic sublattices.

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Quantum Phenomena in Kagome Materials

The Editors of Physical Review Materials are pleased to present the Collection on Quantum Phenomena in Kagome Materials, highlighting cutting-edge advances in theory, synthesis, properties and applications of kagome materials. The Collection is being guest-edited by Mingda Li (MIT), Xiangang Wan (Nanjing University) and Linda Ye (Caltech). Every article published in this collection underwent a rigorous peer review process, adhering to the same high standards applied to all papers. The Physical Review Materials editorial team managed the peer review and made all editorial decisions.

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CCDC 2541457 ( ${TbFe}_{6} {Ge}_{5.77} {Sn}_{0.23}$ ), CCDC 2571238 ( ${TbFe}_{5.13} {Co}_{0.87} {Ge}_{5.68} {Sn}_{0.32}$ ), CCDC 2541459 ( ${Tb}_{0.48} {Fe}_{2.11} {Co}_{0.89} {Ge}_{2.83} {Sn}_{0.17}$ ), CCDC 2541460 ( ${Tb}_{0.48} {Fe}_{1.55} {Co}_{1.45} {Ge}_{2.87} {Sn}_{0.13}$ ), CCDC 2541461 ( ${Tb}_{0.44} {Fe}_{1.21} {Co}_{1.79} {Ge}_{2.81} {Sn}_{0.19}$ ), CCDC 2541462 ( ${Tb}_{0.40} {Fe}_{0.65} {Co}_{2.36} {Ge}_{2.78} {Sn}_{0.22}$ ), CCDC 2541463 ( ${Tb}_{0.35} {Co}_{3} {Ge}_{2.67} {Sn}_{0.33}$ ) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge at www.ccdc.cam.ac.uk/data_request/cif, or by emailing data_request@ccdc.cam.ac.uk, or by contacting the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK.

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Effect of Co doping on structural and magnetic order in kagome magnet $TbF e_{6 - x} C o_{x} G e_{6}$ (nominal $x = 0 - 6$ )

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Quantum Phenomena in Kagome Materials

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Effect of Co doping on structural and magnetic order in kagome magnet TbFe6−xCoxGe6 (nominal x=0−6)

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Physics Subject Headings (PhySH)

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Quantum Phenomena in Kagome Materials

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Supplemental Material

References (60)

Effect of Co doping on structural and magnetic order in kagome magnet $TbF e_{6 - x} C o_{x} G e_{6}$ (nominal $x = 0 - 6$ )