Electronic and magnetic ordered states are strongly correlated to the dimensions of matter. Here we report a dimensional crossover in self-intercalated antiferromagnetic ${\mathrm{V}}_5{\mathrm{S}}_8$ nanoflakes. The transition of three-dimensional (3D) to two-dimensional (2D) transport, evidenced by thickness-independent conductivity, occurs when the thickness of ${\mathrm{V}}_5{\mathrm{S}}_8$ flakes is reduced to ∼7.3 nm. At low temperatures, 3D transport follows Fermi liquid behavior, but 2D transport suggests the emergence of Kondo physics with a logarithmic dependence on the temperature and a negative magnetoresistance of a 5.0 nm thick ${\mathrm{V}}_5{\mathrm{S}}_8$ flake at low temperatures for both in-plane and perpendicular magnetic fields. At temperatures higher than 6 K, the magnetoresistance is positive and parabolically dependent on the magnetic field, indicating suppression of the antiferromagnetic order. Based on a simple magnon gas model, a temperature-independent effective magnon moment $(\sim 1g{\mu }_B)$ is extracted from the Hall coefficient for all ${\mathrm{V}}_5{\mathrm{S}}_8$ flakes with different thicknesses. Our results reveal that dimensional crossover plays an important role in tuning the electronic properties in 2D metallic transition-metal dichalcogenides (TMDs).

中文翻译：

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自插层反铁磁V5S8纳米薄片中的维数交叉

电子和磁性有序状态与物质的维度密切相关。在这里，我们报告了自插层反铁磁中的维度交叉${\mathrm{五}}_5{\mathrm{小号}}_8$纳米薄片。由与厚度无关的电导率证明的三维（3D）到二维（2D）传输的转变发生在当厚度${\mathrm{五}}_5{\mathrm{小号}}_8$薄片减少到~7.3 nm。在低温下，3D 输运遵循费米液体行为，但 2D 输运表明近藤物理学的出现具有对温度的对数依赖性和 5.0 nm 厚的负磁阻${\mathrm{五}}_5{\mathrm{小号}}_8$对于平面内和垂直磁场，在低温下会产生薄片。在高于 6 K 的温度下，磁阻为正且呈抛物线依赖于磁场，表明反铁磁顺序受到抑制。基于一个简单的磁振子气体模型，一个与温度无关的有效磁振矩$(～1G{\mu }_{乙})$从霍尔系数中提取所有${\mathrm{五}}_5{\mathrm{小号}}_8$不同厚度的薄片。我们的研究结果表明，维度交叉在调整二维金属过渡金属二硫化物 (TMD) 的电子特性方面起着重要作用。