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arXiv · 2506.01024

Direct probe of magnetic field effects on phonons by ultrasound propagation in a quasi-two-dimensional honeycomb magnet Na$_2$Co$_2$TeO$_6$

Xiaochen Hong·Maximilian Schiffer·Beat Valentin Schwarze·Marc Uhlarz·Xianghong Jin·Weiliang Yao·Lukas Janssen·Sergei Zherlitsyn·Bernd Büchner·Yuan Li·Young Sun·Christian Hess
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Abstract

We study the phonon behavior of a Co-based honeycomb frustrated magnet Na$_2$Co$_2$TeO$_6$ under magnetic field applied perpendicular to the honeycomb plane. The temperature and field dependence of the sound velocity and sound attenuation unveil prominent spin-lattice coupling in this material, promoting ultrasound as a sensitive probe for magnetic properties. An out-of-plane ferrimagnetic order is determined below the N\'eel temperature $T_N=27$~K. A comprehensive analysis of our data further supports a triple-Q ground state of Na$_2$Co$_2$TeO$_6$. Furthermore, the ultrasound data were systematically compared to the thermal transport results from literature, to unveil the importance of phononic contribution to the observed transport behaviors.

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Xiaochen Hong, Maximilian Schiffer, Beat Valentin Schwarze, Marc Uhlarz, Xianghong Jin, Weiliang Yao, Lukas Janssen, Sergei Zherlitsyn, Bernd Büchner, Yuan Li, Young Sun, Christian Hess. 2025-06-01. Direct probe of magnetic field effects on phonons by ultrasound propagation in a quasi-two-dimensional honeycomb magnet Na$_2$Co$_2$TeO$_6$. https://doi.org/10.1103/kw7z-226c

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