论文标题
锗取代对竞争二氧化钒相的结构和电子稳定性的影响
Influence of germanium substitution on the structural and electronic stability of the competing vanadium dioxide phases
论文作者
论文摘要
我们介绍了一项密度功能理论（DFT）研究，对锗（GE）掺杂的二氧化钒（vo $ _2 $）中的结构，电子和化学键合行为。我们的动机是解释在Ge掺杂下据报道的金属 - 绝缘体过渡温度的升高，并了解在常规DFT水平上可以捕获其背后的基本物理和化学的升高。我们使用超级细胞方法对掺杂型建模，浓度各种浓度和不同的空间分布在vo $ _2 $中。我们的结果表明，GE原子的添加强烈掩盖了高对称金属金红石相位，并诱导结构扭曲，部分类似于实验性绝缘结构的二聚化。因此，我们的工作暗示了对GE掺杂下观察到的过渡温度升高的可能解释，从而激发了进一步的研究，以了解VO $ _2 $中结构和电子过渡的相互作用。
We present a density-functional theory (DFT) study of the structural, electronic, and chemical bonding behaviour in germanium (Ge)-doped vanadium dioxide (VO$_2$). Our motivation is to explain the reported increase of the metal-insulator transition temperature under Ge doping and to understand how much of the fundamental physics and chemistry behind it can be captured at the conventional DFT level. We model doping using a supercell approach, with various concentrations and different spatial distributions of Ge atoms in VO$_2$. Our results suggest that the addition of Ge atoms strongly perturbs the high-symmetry metallic rutile phase and induces structural distortions that partially resemble the dimerization of the experimental insulating structure. Our work, therefore, hints at a possible explanation of the observed increase in transition temperature under Ge doping, motivating further studies into understanding the interplay of structural and electronic transitions in VO$_2$.
