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_1.25Te₂, a layered self-intercalated vdW material which exhibits an antiferromagnetic ordering at T_N ∼191 K followed by a ferromagnetic-like phase transition at T_C ∼171 K. We observe a prominent topological Hall effect and topological Nernst effect between T_C and T_N, 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_1.25Te₂ exhibits a substantial anomalous Nernst effect, featuring a giant Nernst angle of ∼37 % near T_C and a maximum Nernst thermoelectric coefficient of 0.52 μV/K. These results surpass those of conventional ferromagnets and other two-dimensional vdW materials, highlighting Cr_1.25Te₂ as a promising candidate for advanced thermoelectric devices based on the Nernst effect.

中文翻译：

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自插层范德华磁体 Cr1.25Te2 中的巨能斯特角


二维范德华 （vdW） 磁性材料的发现推动了技术设备的进步。能斯特效应在纵向热梯度存在下产生横向电压，在热电应用中显示出巨大的前景。在这项工作中，我们报道了 Cr _1.25 Te 的电子和热电传输特性，Cr Te ₂ 是一种层状自插层 vdW 材料，在 T _N ∼191 K 处表现出反铁磁有序，然后在 T _C ∼171 K 处表现出类似铁磁的相变。我们观察到 T _C 和 T _N 之间突出的拓扑霍尔效应和拓扑 Nernst 效应，这归因于非共面自旋纹理，由于竞争性铁磁和反铁磁相互作用而诱导了实空间 Berry 相。此外，我们表明 Cr _1.25 Te ₂ 表现出显著的反常 Nernst 效应，在 T _C 附近具有 ∼37 % 的巨大 Nernst 角，最大 Nernst 热电系数为 0.52 μV/K。这些结果超过了传统铁磁体和其他二维 vdW 材料的结果，突出了 Cr _1.25 Te ₂ 作为基于 Nernst 效应的先进热电器件的有前途的候选者。