Monolayers of ABTe₄ (A/B = Ti, Zr, Hf) were theoretically predicted to be two-dimensional topological insulators, but little has been known about the physical properties of these compounds. Here, we report on the single crystal growth, bulk transport properties, and band structure calculations of these compounds. The magnetotransport properties indicate that all three compounds are multi-carrier systems. The experimental results of ZrTiTe₄ and HfTiTe₄ can be well fitted by the multi-carrier formula assuming two types of carriers, while three carrier components were necessary for HfZrTe₄. Interestingly, one of the carrier mobilities of HfZrTe₄ exceeded 1000 cm² V⁻¹ s⁻¹, which was nearly one order in magnitude larger than the carrier mobilities of ZrTiTe₄ and HfTiTe₄. Our band structure calculations showed that all three compounds are semimetals consistent with the magnetotransport properties. The band structure around the Γ-point of HfZrTe₄ exhibits features that are distinct from the other two compounds, which is likely the reason of the different carrier properties.

中文翻译：

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范德华材料 ABTe4（A/B = Ti、Zr、Hf）的单晶生长和输运特性

AB Te ₄ ( A / B = Ti, Zr, Hf)单层理论上被预测为二维拓扑绝缘体，但人们对这些化合物的物理性质知之甚少。在这里，我们报告了这些化合物的单晶生长、整体传输特性和能带结构计算。磁输运特性表明所有三种化合物都是多载体系统。_{ZrTiTe 4}和HfTiTe ₄的实验结果可以通过假设两种类型载体的多载体公式很好地拟合，而HfZrTe ₄则需要三种载体成分。_{有趣的是，HfZrTe 4}的载流子迁移率之一超过1000cm ² V ^-1 s ^{-1 ，这比ZrTiTe} ₄和HfTiTe ₄的载流子迁移率大近一个数量级。我们的能带结构计算表明，所有三种化合物都是与磁输运特性一致的半金属。_{HfZrTe 4}的 γ 点周围的能带结构表现出与其他两种化合物不同的特征，这可能是载流子性质不同的原因。