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arXiv · 2412.11213

Giant Nernst Angle in Self-Intercalated van der Waals Magnet Cr$_{1.25}$Te$_2$

Shuvankar Gupta·Olajumoke Oluwatobiloba Emmanuel·Yasemin Ozbek·Mingyu Xu·Weiwei Xie·Pengpeng Zhang·Xianglin Ke
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Abstract

The discovery of two-dimensional van der Waals (vdW) magnetic materials has propelled advancements in technological devices. The Nernst effect, which generates a transverse electric voltage in the presence of a longitudinal thermal gradient, shows great promise for thermoelectric applications. In this work, we report the electronic and thermoelectric transport properties of Cr$_{1.25}$Te$_2$, a layered self-intercalated vdW material which exhibits an antiferromagnetic ordering at TN ~ 191 K followed by a ferromagnetic-like phase transition at TC ~171 K. We observe a prominent topological Hall effect and topological Nernst effect between TC and TN, which is ascribable to non-coplanar spin textures inducing a real-space Berry phase due to competing ferromagnetic and antiferromagnetic interactions. Furthermore, we show that Cr$_{1.25}$Te$_2$ exhibits a substantial anomalous Nernst effect, featuring a giant Nernst angle of ~37% near TC and a maximum Nernst thermoelectric coefficient of 0.52 uV/K. These results surpass those of conventional ferromagnets and other two-dimensional vdW materials, highlighting Cr$_{1.25}$Te$_2$ as a promising candidate for advanced thermoelectric devices based on the Nernst effect.

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Shuvankar Gupta, Olajumoke Oluwatobiloba Emmanuel, Yasemin Ozbek, Mingyu Xu, Weiwei Xie, Pengpeng Zhang, Xianglin Ke. 2024-12-15. Giant Nernst Angle in Self-Intercalated van der Waals Magnet Cr$_{1.25}$Te$_2$. https://doi.org/10.1016/j.mtphys.2024.101627

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