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arXiv · 2407.00963

Contrasting magnetothermal conductivity in sibling Co-based honeycomb-lattice antiferromagnets

Masato Ueno·Takashi Kurumaji·Shunsuke Kitou·Masaki Gen·Yuiga Nakamura·Yusuke Tokunaga·Taka-hisa Arima
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Abstract

Honeycomb-lattice antiferromagnets have attracted wide attention for exploration of exotic heat transport and their interplay with magnetic excitations. In this work, we have revealed a contrasting behavior in the magneto-thermal conductivity (MTC) between two Co-based honeycomb-lattice magnets Co4M2O9 (M = Nb, Ta), despite their identical lattice structures and quite similar magnetism. Co4Ta2O9 exhibits enhanced MTC of about 550% at 9 T of an in-plane magnetic field, comparable to other honeycomb-magnets, while MTC for Co4Nb2O9 reaches only ~30%. This marked difference is ascribed to distinct features in the field-induced evolution of magnetic excitations that resonantly scatter phonons. This finding sheds light on implicit impacts of non-magnetic ions on thermal transport, and hints at the potential for broad heat-transport tunability while preserving magnetism and lattice structures.

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Masato Ueno, Takashi Kurumaji, Shunsuke Kitou, Masaki Gen, Yuiga Nakamura, Yusuke Tokunaga, Taka-hisa Arima. 2024-07-01. Contrasting magnetothermal conductivity in sibling Co-based honeycomb-lattice antiferromagnets. https://doi.org/10.1103/physrevb.110.l041116

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